Notes

Perfumery written from the raw material up. Not brands or reviews — what the bottle in your hand actually is, how it smells, what it blends with, and what the regulations say.

Reading the data · 17 2026-08-01 20 min read How wide is the optical rotation field: a median span of 10 degrees, and the widest entry reads −2400 Several material guides here have recommended measuring optical rotation when a delivery arrives. This piece finishes that advice. 141 materials in the database carry an optical rotation field and have 20 or more suppliers, and the median span of their ranges is 10 degrees. At the narrow end the field really can check a delivery: frankincense oil runs −0.05 to 0.00 and clove bud oil −2.00 to 0.00. At the wide end it discriminates nothing: black pepper oil runs −1 to −23, sixteenth widest of the 141; gurjun balsam oil runs −60 to 0; and expressed lime oil reads +35.00 to −41.00, a range that crosses zero, so a sample measuring 0 is still within spec. The most extreme is Virginia cedarwood oil, whose field reads −2400 to −38.00, a span of 2362. A specific rotation of −2400 degrees is not a thing an essential oil does, and it reads as a misplaced decimal point, on a material with 85 suppliers. Two papers point at the same sentence: a 2024 chiral GC/MS study of commercial tea tree oils found 88 authentic and 12 oxidised samples consistent with the ISO 4730:2017 ranges, yet concluded that comparison to that standard does not always identify adulterated samples.
Reading the data · 18 2026-08-29 27 min read L-theanine against Silexan: on the same anxiety scale, the green tea one did not beat placebo A 2022 Bayesian network meta-analysis in Pharmacol Res put 12 medicinal herbs on one HAMA ranking. L-theanine came out at MD −0.49 with a credible interval running from −6.54 to 5.57, crossing zero, no better than placebo. The one that won on that same table is Silexan (MD −3.84), which is lavender essential oil in a capsule you swallow. Our database draws the line even more plainly: laevo-theanine has 12 suppliers but its odor type, odor, strength and substantivity fields are all empty and the catalogue files it under special dietary and nutritional additives, while lavender oil has 99 suppliers, eight odor words and 12 hours of substantivity, and the notes field of lavender oil france says silexan used as an anti-anxiety agent. This article marks the line between oral evidence and olfactory claims.
Material guide · 109 2025-10-11 18 min read Material guide: musk xylol — the database says "not used for fragrances", and another field on the same record says "fragrance" CAS 81-15-2, 20 suppliers. Its category field reads "information only not used for fragrances or flavors" while the cosmetic_uses field on the same record reads "fragrance; perfuming agents" — one of only two records in 42,225 where both appear, the other being an artificial sweetener. GHS gives it H351, suspected rather than confirmed, and Lehman-McKeeman 1997 explains why: it is uniformly negative in genotoxicity testing yet causes liver tumours in mice, through enzyme induction rather than DNA damage. Müller 1996 found up to 288 ng/g lipid in the adipose tissue of 15 Swiss people. Its acute toxicity, by contrast, is very low.
Material guide · 110 2025-10-15 18 min read Material guide: dihydrocoumarin — one double bond fewer than coumarin, 40× the vapour pressure, 45 degrees lower melting point CAS 119-84-6, 55 suppliers. It differs from coumarin by a single hydrogenated double bond, and three fields change together: vapour pressure goes from 0.1 to 4.0 mmHg (40×), melting point from 68–74 °C to 24–25 °C (so at room temperature it may be liquid or solid), and substantivity from 364 to 228 hours. It sits in a rare combination: of the 1,636 well-supplied materials with a readable vapour pressure, only 10 (0.61%) have both ≥1 mmHg and ≥200 hours substantivity. Its regulatory status is split too — FEMA 2381, JECFA 1171, FCC listed, while cosmetic_uses reads "not used anymore". A 2006 PLoS Genetics paper is titled "The flavoring agent dihydrocoumarin reverses epigenetic silencing and inhibits sirtuin deacetylases".
Material guide · 111 2025-10-19 16 min read Material guide: costus root oil — the notes field says "do not use on any part of the body", and the two sensitising molecules each have their own record CAS 8023-88-9, 21 suppliers. This is the bluntest notes field I have read: "Do not use on any part of the body because of potential sensitizing." The reason sits in the same cell — it contains sesquiterpene lactones reported to cause contact hypersensitivity. What is striking is that those two molecules are separate records in the same database: costus lactone (costunolide, 553-21-9, 7 suppliers) and dehydrocostus lactone (477-43-0, 5 suppliers). In 1982 someone pulled them out of the oil with aminoethyl-polystyrene, and the treated oil could no longer sensitise guinea pigs. And it is still FEMA 2336 today; the flavour line never closed.
Material guide · 112 2025-10-23 19 min read Material guide: civetone — the molecule isolated from a secretion that reads "urine, fecal", and its own odour field opens with "clean" CAS 542-46-1, filed in this database as (Z)-civet decenone, 10 suppliers. Putting it next to its source is instructive: civet absolute's odour field reads animal, urine, fecal, honey, evaluated at 10%. The molecule isolated from it has odour type musk, opens with "clean", and is evaluated at 1%. The (E) isomer in the same database has zero suppliers. In 2017 someone made nine fluorinated civetone analogues and confirmed the ring conformations by X-ray — the ones pushed away from the consensus conformation lost their musk odour and became less pleasant.
Material guide · 113 2025-10-27 17 min read Material guide: castoreum absolute — the composition was redone in 1993 and 1995, and only 8 of the 24 previously reported compounds were confirmed CAS 8023-83-4, 23 suppliers, the best-supplied record in the tariff-0510 group. It has no FEMA number (the one that does is castoreum liquid, FEMA 2262), and all three toxicity fields are undetermined. Its odour reads leathery, smoky, animal, phenolic, old wood, burnt. The compositional history is worth reading: Tang and colleagues reanalysed North American beaver castoreum in two papers in 1993 and 1995 — the phenolics paper confirmed only 5 of 15 previously reported compounds and found 10 new ones; the neutrals paper confirmed only 3 of the 9 reported by Lederer in 1949 and found 13 new ones. Together, 8 of 24 survived and 23 were added.
Material guide · 114 2025-10-31 20 min read Material guide: ambrein — the main constituent of ambergris, two suppliers, and a notes field that gets the whale wrong CAS 473-03-0, C30H52O, two suppliers. It is the principal constituent of ambergris and the upstream of ambroxan — Moser 2020 puts it plainly: on oxidative degradation of (+)-ambrein several fragrance molecules form, among them (−)-ambrox, one of the highest valued compounds in perfumery. Its physical properties are extreme: logP 9.60, boiling point 495 °C, water solubility 6.9×10⁻⁷ mg/L. And the database's notes field says it comes from the intestinal secretion of the "sperm blue whale" — sperm whales and blue whales are different animals, and the binomial is misspelled too. Of the ten ambergris-related records in the same database, only two carry a CAS pointing at a defined substance.
Material guide · 115 2025-11-04 17 min read Material guide: angelica root oil — the odour field says musk and ambrette, and the main constituents are three monoterpenes CAS 8015-64-3, 46 suppliers, FEMA 2088. Its odour field carries eleven words, among them ambrette and musk. But Aćimović's 2017 analysis reports that the roots contain 0.10% essential oil, with α-pinene at 29.7%, δ-3-carene at 14.2% and a β-phellandrene/limonene mixture at 13.2%. All three are monoterpenes, and none of them is a musk. That also explains an odd pair of fields: the odour type is amber while substantivity is only 31 hours. The same record's notes field says "this oil should not be used anywhere on the body because of its phototoxic effects", and the GHS field gives it skin sensitisation Category 1.
Material guide · 116 2025-11-08 18 min read Material guide: Peru balsam — its constituent list is a roll-call of molecules this series has already written up CAS 8007-00-9, shared by eight records: oil at 41 suppliers, the balsam itself at 29, absolute at 21, resinoid at 20. De Groot's 2025 analysis of the resin used to make patch-test allergens found the main volatiles to be benzyl benzoate, (E)-nerolidol, benzoic acid, benzyl alcohol, (E)-cinnamic acid, vanillin and (E)-benzyl cinnamate — four of which already have their own articles here. In dermatology it sits in the baseline patch-test series: Guarneri 2021 tested 12,030 patients with both Peru balsam and fragrance mix 1, each returning 3.6% positive, with only 1.0% overlapping — each catching about 2.5% the other missed.
Material guide · 117 2025-11-12 17 min read Material guide: WS-3 — its job is not to smell like anything, and its flavour field uses the word "trigeminal" CAS 39711-79-0, 36 suppliers, FEMA 3455. Its strength field reads low, its vapour pressure is 0.000085 mmHg, and the two describers on its record disagree — one calls it mild mentholic (at 25%), the other virtually odourless (at 10%). The real content is in the flavour field, where Mosciano records an "intense lingering cooling trigeminal effect" at 10 to 100 ppm. Trigeminal, not olfactory. Klein 2011 places it on a potency ladder: two new menthol derivatives are 40 to 200 times more potent than menthol and WS-3 at TRPM8. And Erythropel 2020 found WS-3 in EU Juul mint liquids and absent from the US and Canadian ones.
Material guide · 118 2025-11-20 17 min read Material guide: camphene — the puzzle left open last time resolves as "camphene" not being one thing CAS 79-92-5, 39 suppliers, FEMA 2229. When I wrote about the two describers' vocabulary last round, camphene was the case that would not resolve — both stated 10% and their words barely overlap. The answer is in the formulations field: commercial product may contain about 20% tricyclene, and commercial grade starts at 75% purity. The assay field reads 80 to 100, and the same database lists supplier entries for "Camphene 46%" and "Camphene 94%". Huang 2020 supplies the cause — camphene is made industrially by isomerising α-pinene, and that reaction's selectivity to camphene tops out at 78.5%. It is also a solid melting at 51 °C with a flash point of 35 °C, classified GHS as a flammable solid.
Material guide · 119 2025-11-24 17 min read Material guide: rhodinol — one name over two isomers, two botanical sources, and an optical rotation nobody can smell CAS 141-25-3, 41 suppliers, FEMA 2980. It has the widest assay range of any fragrance material in this database — 70.00 to 100.00, thirty percentage points. The reason is in the name: the head_synonym field reads "3,7-dimethyl-6 & 7-octen-1-ol", two positional isomers under one trade name. And the supplier entries list "RHODINOL EX-CITRONNELLA" alongside "RHODINOL EX-GERANIUM" — one name, two plants. Its optical rotation field is a range too (−5 to −10), meaning enantiomeric composition varies between lots — but when Laska ran a triangular test on 20 subjects in 1999, beta-citronellol was one of the seven pairs they could not tell apart.
Material guide · 120 2025-11-28 15 min read Material guide: beta-caryophyllene — it has a named receptor target, and that receptor has nothing to do with smell CAS 87-44-5, 61 suppliers, FEMA 2252. It is a shared constituent of clove, cinnamon, mint, eucalyptus, thyme and lemon balm, with an odour field reading sweet, woody, spicy, clove, dry and 44 hours of substantivity. What made it famous is something else: Gertsch and colleagues showed in PNAS in 2008 that (E)-beta-caryophyllene selectively binds the cannabinoid type 2 receptor at Ki 155 nM and is a functional CB2 agonist — their paper is titled "Beta-caryophyllene is a dietary cannabinoid". The record also carries an internal contradiction worth noting: the GHS field gives it acute oral toxicity Category 4 (H302, harmful if swallowed) while the toxicity field on the same record reads oral rat LD50 above 5000 mg/kg — beyond even the Category 5 threshold.
Material guide · 121 2025-12-02 14 min read Material guide: nerolidol — four layers of isomerism on one CAS, and the database gives cis and trans different odour types CAS 7212-44-4, 54 suppliers, FEMA 2772. Its assay field reads "96.00 to 100.00 sum of isomers" and its optical rotation field reads "−2.00 to +2.00" — a range that crosses zero. Meanwhile (E)-nerolidol and (Z)-nerolidol are separate records in the same database, with odour types floral and waxy respectively. The notes field adds that the (S)-enantiomer is the commoner one and occurs mostly as the (S)-(E)-isomer. Its strength field reads low at rank 1, yet substantivity is 100 hours. Chan's 2016 review supplies a biological position: nerolidol is an intermediate in the plant's synthesis of DMNT, a volatile induced only after herbivore damage.
Material guide · 122 2025-12-06 15 min read Material guide: pine oil — two entirely different manufacturing routes under one name, with the grade written into the product name CAS 8002-09-3, 38 suppliers, assay 80.00 to 100.00. The TSCA definition calls it a product of "the high temperature distillation of oil of turpentine residues or by the catalytic hydration of pinenes" — two chemically unrelated routes sharing one name and one CAS. Supplier entries list PINE OIL 50%, 65% and 90% side by side, and the same database carries separate records for "pine oil 60" (assay 60 to 100) and "pine oil 85": the grade is in the product name. It is also one of the few records here with human toxicity data — of the 5,185 records with oral toxicity data, only 129 (2.5%) include a human figure.
Material guide · 123 2025-12-10 17 min read Material guide: methyl salicylate — the only oral-woman record in the database, and the paper that actually matters measured skin CAS 119-36-8, 88 suppliers, FEMA 2745. Wintergreen is this molecule — the odour field reads wintergreen, minty, sweet, root beer, phenolic. Its toxicity field lists eight rodent LD50s and then one line: "oral-woman LDLo 355 mg/kg", the only record labelled woman among the database's 156 human entries. But an ingestion figure is not what a perfumer should be reading. Martin 2004 measured the route that matters: eight subjects wearing eight commercial patches for eight hours reached a plasma peak of 29.5 ng/mL for methyl salicylate. Bell 2002 supplied the risk multiplier — broken skin plus an occlusive dressing. And its cosmetic_uses field carries an unusual value: denaturants. It is used to denature alcohol.
Material guide · 124 2025-12-14 16 min read Material guide: tea tree oil — the essential oil with the most published allergy cases, and a dermal toxicity field containing one line about a rabbit CAS 8022-72-8, 101 suppliers, FEMA 3902. De Groot and Schmidt's 2016 review in Contact Dermatitis puts it plainly: of all essential oils, tea tree oil has caused the most published allergic reactions since the first cases in 1991, with patch-test positivity in routine testing running from 0.1% to 3.5%. Fresh tea tree oil is only a weak-to-moderate sensitiser — oxidation raises its allergenic potency, and the sensitisers include ascaridole. Christoffers 2014 measured ascaridole's patch-test concentration: 1.4% positive at 1%, 5.5% at 2%, 7.2% at 5% — while irritant reactions rose too. And this material's dermal toxicity field in the database reads, in full, "skin-rabbit LDLo 5000 mg/kg".
Material guide · 125 2025-12-18 16 min read Material guide: bitter almond oil — an empty assay field, a formula reading "unspecified", and a supplier label saying "benzaldehyde >95%" CAS 8013-76-1, 37 suppliers, FEMA 2046. Its assay field is entirely blank and its formula field reads unspecified, while a supplier entry says "bitter Almond Essential oil Morocco Benzaldehyde (>95%)" — so more than 95% of the oil is a single molecule that has its own record with 108 suppliers. Substantivity reads "< 3 hours", shelf life is only 12 months where most materials say 24, and strength rank is 3. Its oral toxicity field carries an oral-human LDLo of 107 mg/kg, among the lowest of the database's 156 human entries. And Jaswal's 2018 review supplies the mechanism that matters: intravenous administration produces no hydrogen cyanide — it takes gut bacteria hydrolysing amygdalin to make it. Toxicity depends on route.
Material guide · 126 2025-12-22 18 min read Material guide: camphor — its odour field holds one word, and that word is its own name CAS 76-22-2, 66 suppliers, FEMA 4513. Its odour type is camphoreous, its odour field is camphoreous, its flavour field is camphoreous and its taste description is camphoreous — four fields, one word, and that word is the material's own name. It has no strength field and no substantivity field. Its cosmetic_uses reads denaturants, fragrance, plasticisers. And it is one of the few materials here with data on all three toxicity routes — oral, subcutaneous, and the inhalation route that only 6.6% of records carry. Xu 2005 showed in J Neurosci that camphor activates and strongly desensitises TRPV1, at a site distinct from capsaicin's — which is how it works as a topical analgesic.
Material guide · 127 2025-12-26 18 min read Material guide: birch tar — archaeologists call it the oldest synthetic substance humans made, and 30 suppliers sell it today CAS 8001-88-5, 30 suppliers. Odour type smoky; odour smoky, burnt wood, leathery, phenolic. The strength field recommends evaluating at 1.00% or less — among the lowest evaluation concentrations in this series. The notes field gives a purchasing instruction outright: 'For perfumery purposes, only the rectified oil of Birch Bark Tar should be considered. Not really an essential oil.' And the supplier entries list Birch Tar Crude and Birch Tar Rectified side by side. Specific gravity runs 1.13 to 1.35 and refractive index 1.522 to 1.590 — both unusually wide. Schmidt and colleagues open their 2023 paper in Archaeological and Anthropological Sciences with a single line: birch tar is the oldest synthetic substance made by early humans.
Material guide · 128 2026-01-12 18 min read Material guide: treemoss absolute — the thing people react to may not come from the lichen CAS 68648-41-9, 29 suppliers, odour woody, dry, forest, seaweed, herbal, green. The notes field opens with an instruction: 'Do not use on any part of the body because of sensitizing potential.' It does not say which sensitiser. Treemoss is a lichen that grows on conifers, and harvesting it brings along colophony from the bark. Uter and colleagues analysed 3,030 patients patch tested with all three antigens in 2012: 6.37% positive to treemoss, 5.71% to oakmoss, 4.82% to colophonium — and treemoss-positive patients split into two subgroups, one sensitised to the resin acids in colophony and one not. Paulsen and Andersen put it more bluntly in 2019: of the eight patients positive to treemoss alone, 75% had clinically relevant reactions to colophonium.
Material guide · 129 2026-01-28 16 min read Material guide: mace oil — the same seed as nutmeg, just the red net around it CAS 8007-12-3, 34 suppliers. This record's synonym field is not a synonym, it is a definition: 'essential oil steam-distilled from the dried red case which surrounds the ripe seeds of the nutmeg.' Mace is not a different plant, it is the red lacy aril wrapped around the same fruit's seed. Ashokkumar and colleagues' 2022 review lays out oil yields for four tissues, and mace at 8.1 to 10.3% is both the highest and the narrowest range. And the toxicity field carries a human entry: oral-man TDLo 400 mg/kg, with the recorded effects being 'hallucinations, distorted perceptions,' toxic psychosis and cardiac arrhythmias, sourced to the American Journal of Emergency Medicine in 1992. Ehrenpreis and colleagues reviewed ten years of Illinois Poison Center data in 2014: 32 nutmeg ingestions reported, 17 of them unintentional, and 10 of those 17 in people under 13.
Material guide · 130 2026-02-13 18 min read Material guide: isovaleric acid — the database writes 'stinky feet,' and it is not a figure of speech CAS 503-74-2, 67 suppliers, FEMA 3102. The odour field reads sour, sweaty, cheesy, tropical, dairy, acidic, pungent, fruity, ripe, fatty — and one evaluation entry reads 'sour stinky feet sweaty cheese tropical' while another simply says 'disagreeable.' Both are literal. Ara and colleagues confirmed in the Canadian Journal of Microbiology in 2006 that foot odour is isovaleric acid, produced when Staphylococcus epidermidis degrades the leucine in sweat. The end of that paper is the good part: they screened fragrance materials and found citral, citronellal and geraniol inhibit isovaleric acid generation at low concentrations. Strength rank 3, evaluate at 1% or less, substantivity 400 hours.
Material guide · 131 2026-03-01 18 min read Material guide: β-damascone — two records under one FEMA number, and only the obscure one carries the sensitisation warning The database holds two β-damascone records: (E)-β-damascone (#11165, 41 suppliers) and β-damascone (#11159, 11 suppliers). They share FEMA 3243, the same formula, the same 200 °C boiling point and the same logP of 3.50. But substantivity reads 264 hours on one and 191 on the other; storage says refrigerate on one and cool dry place on the other; toxicity gives an oral LD50 of 2920 mg/kg on one and 'not determined' on the other. The striking one is GHS: the record with 11 suppliers carries H317, may cause an allergic skin reaction, and the record with 41 suppliers has an empty GHS field. Giménez-Arnau and colleagues' 2002 case only identified α-damascone as one of the culprits by taking a bottle of perfume apart — the standard fragrance mix patch test was negative.
Material guide · 132 2026-03-17 18 min read Material guide: lavandin oil — three records define themselves with the same sentence and get different CAS numbers and different odour types The database holds three lavandin oil records: grosso (66 suppliers), lavandin oil (51), abrialis (36). All three share FEMA 2618, but there are two CAS numbers between them. The strangest part is the middle pair: lavandin oil and abrialis lavandin oil have word-for-word identical synonym fields — 'essential oil distilled from the flowering herbs of the lavandin, Lavandula hybrida var. abrial' — identical specific gravity, refractive index, 216-hour substantivity and strength rank, yet different CAS numbers, and one is typed floral while the other is typed herbal. D'Addabbo and colleagues measured three lavandin cultivars in 2021 and found linalool running from 40% to 66%. And the lavandin oil record's notes field carries a TSCA definition for Convolvulus scoparius, a bindweed with no connection to lavender.
Material guide · 133 2026-03-29 17 min read Material guide: allyl isothiocyanate — the notes field says 'used in the manufacture of flavors, war gases,' and it does not exist in the intact plant CAS 57-06-7, 53 suppliers, FEMA 2034. The odour field holds two words: pungent, mustard. Its evaluation concentration is 0.01%, the lowest tier among the database's thinly-described records. The notes field opens with 'used in the manufacture of flavors, war gases; medical use as a counterirritant.' Two things are worth keeping. First, it does not exist in intact mustard, wasabi or horseradish — those plants store the glucosinolate and the enzyme myrosinase apart, and the two meet only when you cut or chew. Second, Jordt and colleagues showed in Nature in 2004 that it, capsaicin and THC excite the same population of sensory neurons, and that it and THC act through the same ion channel, ANKTM1. Dermal LD50 88 mg/kg.
Material guide · 134 2026-04-18 16 min read Material guide: methyl mercaptan — an odour threshold of 0.02 ppb in water, and the main component of bad breath CAS 74-93-1, 50 suppliers, FEMA 2716. Its boiling point is 6.1 °C — at room temperature it is a gas. The evaluation field records an odour threshold in water of 0.02 ppb and a flavour threshold of 2 ppb, a hundredfold apart. It is one of the 107 records the database evaluates at 0.01%. The odour field reads cabbage, garlic, vegetable, oily, alliaceous, eggy, creamy, savory — and two evaluations in that same field, taken at different concentrations, say different things: at 0.01% 'decomposing cabbage garlic', at 1.00% 'vegetable oil, alliaceous, eggy, creamy with savory nuances'. Stephen and colleagues measured it in patients' mouths with a portable gas chromatograph in 2021.
Material guide · 135 2026-05-04 14 min read Material guide: pear ester — it makes a pear smell like a pear, and apple orchards use it to trap codling moths CAS 3025-30-7, 46 suppliers, FEMA 3148. The database's evaluation field states it outright: 'the characteristic odor of Bartlett Pear.' This is where that smell comes from, and the trade simply calls it pear ester. Strength rank 3, evaluate at 10% or less, substantivity over 48 hours. And it has a second identity: Mitchell and colleagues, working in New Zealand apple orchards in 2008, found that the codling moth's sex pheromone catches only males, while this pear ester catches females — and female catch rises with dose, peaking at 10 mg. Incidentally, this record's refractive index field reads 1.48000 to 1.14860. The second number has an extra 1 in it.
Material guide · 136 2026-05-16 16 min read Material guide: furaneol — the strawberry makes it, then attaches a sugar and puts it away CAS 3658-77-3, 101 suppliers, FEMA 3174. Its synonym field reads 'furaneol (Firmenich)' — a trademark that became the common name. The odour field is sweet, cotton candy, caramellic, strawberry, brown sugar, burnt, savory, and its descriptions differ between 0.10% and 1.00%. It is a white to pale yellow solid melting at 78–81 °C, and its substantivity is recorded as 320 hours at 20% in dipropylene glycol — because it is not a liquid and cannot be evaluated neat. Raab and colleagues identified the strawberry enzyme that makes it, FaQR, in The Plant Cell in 2006, and Yamada and colleagues found in 2018 that the plant uses a dedicated glucosyltransferase to attach glucose and store it. It is also one of the sixteen same-type materials in my last article's clique.
Material guide · 137 2026-06-01 15 min read Material guide: nootkatone — it smells of grapefruit, it is named after an Alaskan cypress, and it is now used to repel ticks CAS 4674-50-4, 104 suppliers, FEMA 3166. It is a white crystal melting at 32–37 °C, which is why its substantivity is recorded as 236 hours at 20% in DPG. The odour field reads grapefruit peel, citrus, gardenia, woody, and the taste field adds one more word: bitter. Its name comes from Callitropsis nootkatensis, the Alaska yellow cedar, because the synthase for its precursor valencene was cloned from that tree. Siegel and colleagues measured its repellency against three human-biting tick species in 2023: Ixodes scapularis, the Lyme disease vector, was repelled at 0.87 µg/cm², while the other two needed 252 µg/cm² or more. Incidentally, this record's evaluation field contains the line 'This material is NOT to be used as a fragrance ingredient,' while the same record's cosmetic uses field reads 'perfuming agents.'
Material guide · 138 2026-06-17 13 min read Material guide: buchu mercaptan — Cramer Class III, toxicity 'not determined', 89 suppliers, and 0.2 ppm in a beverage CAS 38462-22-5, 89 suppliers, FEMA 3177. It is the best-supplied material in Cramer Class III, and its oral toxicity field reads 'not determined'. The odour field is an unusual combination: sulfurous, minty, green, fruity, berry, buchu, tropical, peach, raspberry — one molecule spanning sulfur and fruit. It is the core of cassis, and the notes field says a mixture of stereoisomers is what gets used as a blackcurrant flavour. The taste field gives something rare in this series: a complete dosage ladder — up to 6 ppm in desserts, 1–2 ppm in bakery and soft confections, 0.2 to 0.4 ppm in beverages. That is how this system works: no toxicity data, exposure controlled instead.
Material guide · 139 2026-07-08 15 min read Material guide: allyl hexanoate — the database's most flavour-tagged material (67 of them), and its GHS says toxic if swallowed, toxic in contact with skin CAS 123-68-2, 82 suppliers, FEMA 2032. It is the workhorse of pineapple flavour, and the uses field hangs 67 FL tags on it — more than any other record. The notes field simultaneously says it goes into apple blossom, peach blossom and wisteria perfume compositions, which straddles exactly the divide I measured last time. But its GHS carries H301 (toxic if swallowed) and H311 (toxic in contact with skin), with an oral rat LD50 of 218 mg/kg and a rabbit dermal LD50 of 300. The reason is metabolic: allyl esters hydrolyse to allyl alcohol, and Karas and Chakrabarti showed in 2001 that the resulting liver injury depends on liver alcohol dehydrogenase — block that enzyme and the damage does not happen at all. Substantivity under one hour.
Material guide · 140 2026-07-20 16 min read Material guide: raspberry ketone methyl ether — a berry molecule that makes up 2.40% of agarwood oil CAS 104-20-1, 54 suppliers, FEMA 2672. It is one of the database's few genuinely balanced dual-use materials: 52 flavour tags against 45 fragrance tags. The odour field runs to twelve words — sweet, dry, raspberry, rose, cherry, fruity, acacia, woody, powdery, honey, vanilla, violet — and one evaluator called it ionone-like. The surprise is its occurrence field: agarwood oil at 2.40%, aloe wood, anise seed. A berry molecule making up 2.4% of oud. And agarwood has a precondition — Xu and colleagues put it plainly in 2013: only wounded trees can produce it. Substantivity 324 hours measured neat, Cramer Class I, oral LD50 over 5000 mg/kg.
Material guide · 141 2026-08-09 14 min read Material guide: hay absolute — the molecule that makes hay smell of hay became, once mouldy, the ancestor of warfarin CAS 8031-00-3, 34 suppliers. The odour field reads sweet, hay, woody, tobacco, mossy, tonka, and one evaluation entry is 'meadow with wild grass and flowers in summer'. Its synonym field says perennial ryegrass absolute while the TSCA definition in its notes says Hierochloe — two different plants in one record. Hay's smell is coumarin, and coumarin has a hard history: in 1920s North America, cattle eating mouldy sweet clover hay bled to death, the causative agent dicoumarol was isolated in Link's laboratory in 1940, a family of related compounds followed, and the most popular of them turned out to be warfarin. Substantivity 400 hours measured neat, and the toxicity field reads 'not determined'.
Material guide · 143 2026-09-06 14 min read Material guide: diacetyl — its inhalation toxicity field reads 'not determined', and it is the molecule famous for causing a lung disease CAS 431-03-8, 66 suppliers, FEMA 2370. It is the core of butter flavour, and its toxicity_inhalation field reads 'Not determined'. That is worth pausing on: diacetyl is the cause of popcorn lung. Hubbs and colleagues open their 2019 review with 'flavorings-related lung disease is a potentially disabling and sometimes fatal lung disease of workers making or using flavorings', and Park and Gilbert's 2018 risk assessment at a microwave popcorn plant put a lifetime respiratory impairment prevalence of one per thousand at 0.005 ppm of diacetyl exposure. Its flash point is 7.22 °C — lower than ethanol's. And it occurs naturally in butter, cheese, coffee, honey, lavender oil and geranium oil.
Material guide · 144 2026-09-14 15 min read Material guide: acetoin — its vapour pressure puts it in the top band, and it lasts 28 hours CAS 513-86-0, 105 suppliers, FEMA 2008. Its vapour pressure is 2.69 mmHg, squarely in the top band I computed last time, where the median substantivity is 4 hours. This lasts 28 — seven times the median. The clue is in the physical properties: a melting point of 90–91 °C against a boiling point of only 147. A liquid whose melting point sits 57 degrees below its boiling point makes no sense unless that melting point is measuring something else. Acetoin dimerises on standing into a crystalline solid, and the appearance field duly reads 'liquid to solid'. It is also diacetyl's other half: in the microbial butanediol cycle acetoin and diacetyl interconvert, and what Menéndez and colleagues measured during the ripening of Spanish Arzúa-Ulloa cheese in 2000 was the combined 'diacetyl-acetoin' content.
Material guide · 159 2025-12-30 16 min read Material guide: musk ambrette — three fields saying don't use it, and a replacer that tops the corpus CAS 83-66-9, 18 suppliers. Three fields in this record say the same thing: the category field reads information only not used for fragrances or flavors, the regulatory field reads FEMA GRAS (withdrawn), CoE, and the cosmetic uses field reads not used anymore. The notes field gives the reason: a widely used fragrance implicated in contact photosensitivity. Across 954 formulas it appears zero times, while musk ambrette replacer appears 56 times, the most-used replacer in the whole corpus. Three nitro musks sit in three different states in this database: musk ketone is entirely normal, musk ambrette has all three fields saying no, and musk xylol's category field says no while its cosmetic uses field says yes. Its oral rat LD50 of 339 mg/kg puts it in the lowest 6.7% of the 1,282 fragrance materials carrying that value, but what removed it from use was photoallergy rather than acute toxicity.
Material guide · 160 2026-01-16 16 min read Material guide: 7-methyl coumarin — its notes field reads None found, and its isomer is the one with the problem CAS 2445-83-2, 7 suppliers, C10H8O2. Its category field reads 'information only not used for fragrances or flavors', its cosmetic uses field reads 'not used anymore', and its notes field reads 'None found': the database tells you not to use it without saying why. Its isomer, 6-methyl coumarin, does say why. That record's notes field reads 'synthetic fragrance causing contact photoallergy', and it has 35 suppliers, four regulatory listings and continued use. This record also has two fields fighting each other. Its atmospheric boiling point reads 128 °C, the same number as the lower bound of its melting point at 128 to 130 °C, while its appearance field says pale white powder. Only 11 records in the database have identical boiling and melting point fields, and this is the only one where the boiling point is the broken half. Its strength field reads low while recommending evaluation at 1% or less; of 253 strength rank 1 materials, it is the only one that does, and rank 1's median recommendation is 10%.
Material guide · 161 2026-02-01 16 min read Material guide: dipentene — its optical rotation field is empty, and that is correct CAS 138-86-3, 37 suppliers, C10H16. It is racemic limonene, and the database's optical rotation field is empty. That is not an omission but the right answer: two mirror-image molecules in equal amounts leave polarised light unmoved. Its two single enantiomers read +87 to +102 and -118 to -108. But the vapour pressures across those three records do not agree: dipentene reads 1.550 mmHg, the laevo form 1.541, and the dextro form 0.198, a factor of 7.8. Enantiomers have identical vapour pressures by definition and a racemate's is nearly identical, so the 0.198 is the outlier. And I used it in #109, where I set d-limonene's 0.198 beside 2-acetyl pyrazine's 0.188 and said two materials of similar volatility differed a hundredfold in substantivity. That comparison no longer stands. Its notes field also carries an uncleaned ==(R)== markup, one of only two records in the database that do.
Material guide · 162 2026-02-17 17 min read Material guide: 2-methyl undecanal (aldehyde C-12 MNA) — one wrong boiling point that dragged the vapour pressure with it CAS 110-41-8, 40 suppliers, C12H24O. Its boiling point field carries two values at the same pressure, 171 °C and 233 °C, 62 degrees apart. The homologous series settles it: 2-methyl decanal, one carbon shorter, is registered at 170 °C, and adding a carbon cannot raise a boiling point by one degree. Straight-chain undecanal is 223 °C, so a branched twelve-carbon aldehyde landing near 233 is the sensible reading. What makes this interesting is that the error did not stop at the boiling point. Its vapour pressure reads 1.428 mmHg marked est, and the relationship I fitted across 8,048 materials returns 1.94 for a boiling point of 171 and 0.039 for 233, while dodecanal, the same molecular formula, is registered at 0.034. That estimated vapour pressure looks like it was computed from the wrong boiling point. In the corpus, merging five spellings gives 67 formulas at a median dose of 1.00%, and its odour field runs to ten words including metallic and gassy.
Material guide · 163 2026-03-05 17 min read Material guide: maple furanone — recommended at 0.01% or less, with an empty strength rank CAS 698-10-2, 67 suppliers, C7H10O3. Its strength field reads very high and recommends evaluating at 0.01% or less, a dilution asked for by only 9 materials in the whole database, and this is the best-supplied of them. Yet its strength_rank field is empty. Checking why turned up something systematic: that field has three levels while the adjective has four. Low maps to rank 1, medium to rank 2 and high to rank 3 without a single exception, and all twelve very high materials carry no numeric rank at all. The twelve strongest materials in this database do not exist in the strength rank column. It has three other problems: two boiling points at 0.50 mmHg (102–103 and 83–86) with neither marked est; a melting range of 31 to 35 °C identical to shoyu furanone's, which shares its molecular formula but not its CAS number; and vapour pressures 353-fold apart between the two.
Material guide · 164 2026-03-21 17 min read Material guide: dodecanal (aldehyde C-12 lauric) — vapour pressure lines up neatly along the carbon chain, the longevity column refuses to CAS 112-54-9, 53 suppliers, C12H24O. Line up the straight-chain aldehydes from C-8 to C-14 and vapour pressure falls monotonically, spanning 345-fold, a textbook staircase. Longevity won't queue: 7, 276, 224, 72, 368, 400 hours, with C-11 five times shorter than C-12. Digging in, the tidy column turns out to be six estimated values, while the messy one is what people actually smelled on blotters. Its natural occurrence is counterintuitive too: the first word in its odor field is soapy, citrus peel oils carry only 0.002 to 0.055%, and the richest natural source is coriander leaf oil at 4.96 to 10.30%. Two more things: the database notes field recommends pairing it with lilyall for a clean fresh accord, a material banned in the EU since 2022; and a University of Tokyo team found it in the wrist-gland secretions of ring-tailed lemurs, rising with testosterone in the breeding season.
Material guide · 165 2026-04-02 24 min read Material guide: 3-mercaptohexyl acetate (3-MHA) — 65 of the database's 85 thiols are filed under something foul, this one is filed fruity CAS 136954-20-6, 35 suppliers, C8H16O2S. The database holds 257 materials with mercapto, thiol or sulfanyl in the name; 85 of them carry an odor family, and 65 of those sit in the sulfurous, meaty, onion or rotting-vegetable end. Only three are filed fruity, and only one of the three is actually buyable: the other two have 3 and 7 suppliers. Read further down the same record, though, and the odor field says passion fruit, blackberry, blackcurrant bud while the flavor field says sulfurous, roasted, onion, durian. One molecule, two fields, two different materials. The difference hides in each field's measurement conditions: the odor was smelled at 0.10% in DPG, while the flavor field's usage note reads tropical fruit at 0.5 to 1 ppm. A 2000 Bordeaux study showed that passion fruit stores no aroma at all, only an odourless cysteine conjugate. A 2003 Belgian study synthesised 21 mercapto esters for sensory comparison and concluded this family sits at the higher-threshold end of the thiols. And the record contradicts itself: the main fields give a boiling point of 186 °C, a note further down says 240 °C.
Material guide · 166 2026-04-06 22 min read Material guide: clove bud oil — twelve records under one CAS number, and bud, leaf and stem are three different products CAS 8000-34-8, 128 suppliers, 8th in the whole site by supplier count. That CAS number does not point at one material in this database, it points at twelve: bud oil, leaf oil, stem oil, bud concrete, absolute, resinoid, oleoresin, CO2 extract, leaf absolute, terpeneless leaf oil. One number covering three plant parts and six extraction methods. The three main oils each carry their own FEMA number (2323, 2325, 2328), have different odor fields, longevities of 188, 116 and 176 hours, and specific gravity ranges that do not overlap. Bud and leaf oil also share a boiling point field of 251 °C, which is a number no mixture should have. The safety section is worth stopping on: both oils are classified for skin, eye and respiratory irritation with no sensitisation line, yet a 2021 review puts eugenol at 50% or more of the oil, and eugenol's own GHS entry opens with skin sensitisation category 1. A 2023 study across six European dermatology clinics measured positive eugenol patch tests down to 0.031%.
Material guide · 167 2026-04-22 22 min read Material guide: basil oil — the word anisic in the odor family field is the chemotype's signature CAS 8015-73-4, 110 suppliers. The first thing to know about basil oil is that buying basil oil does not get you a definite thing. One CAS number carries twelve records in this database, and their odor families split three ways: anisic six, licorice four, herbal one. The source data itself leaks the answer, because the odour-sample notes name Lemon basil CT Citral and Sweet Basil CT Linalool Oil, and CT stands for chemotype. In 2008 Mississippi State grew 38 sweet basil accessions in one field and sorted them into seven chemotypes: high-linalool at 19 to 73%, methyl chavicol at 20 to 72%, methyl eugenol reaching 91% in one accession, with oil content ranging 0.07% to 1.92%, a 27-fold spread. Same species, same field, same season, so the difference is genetic. And methyl chavicol is estragole, which is metabolised into a genotoxic 1'-sulfoxy metabolite. The 2013 Wageningen paper is the one to remember: powdered basil contains nevadensin, which inhibits that activation pathway, while basil essential oil carries little of it. The plant brings its own brake; the distillate does not.
Material guide · 168 2026-05-08 20 min read Material guide: ginger root oil — the heat is not in the oil, distillation left it in the pot CAS 8007-08-7, 104 suppliers. The odor field for ginger oil reads spicy, woody, terpenic, warm, ginger, citrus. Not one word about heat, and that is not an omission. Ginger's heat comes from the gingerols and shogaols, which have records in this database too, with 8 suppliers for (6)-gingerol and 6 for 6-shogaol, and every one of those records has an empty odor family and an empty odor field. They do not evaporate, so steam distillation never catches them, and the distilled oil carries no heat. What carries heat is the oleoresin, which sits under a different CAS (8002-60-6), with the CO2 extract under a third. A 2024 review describes gingerols activating TRPV1, the capsaicin receptor, to produce pungency. There is a second surprise in the composition: in 2006 Southern Cross University distilled 17 ginger clones and 16 of them ran 51 to 71% citral, with a neral-to-geranial ratio steady at 0.61 plus or minus 0.01. Citral is one of the 26 allergens the EU requires to be named, and it sensitises once oxidised, which probably explains why ginger oil's shelf life is listed at only 12 months.
Material guide · 169 2026-05-20 21 min read Material guide: ethyl acetate — it appears in 1,977 other materials' solubility fields, and it is a fragrance material itself CAS 141-78-6, 105 suppliers. This material's category field reads flavor and fragrance agents plus carrier solvents, and its cosmetic uses field reads perfuming agents and solvents. It is one of the few materials that shows up inside other records: of the 23,941 materials with a solubility field, 1,977 mention ethyl acetate in it, putting it fourth behind water, alcohol and propylene glycol. The physical data is extreme too. Vapour pressure 111.7 mmHg, with only 146 of the 9,020 materials that carry a vapour pressure record sitting above it. Longevity 4 hours. Flash point −4.44 °C, colder than a refrigerator. Of the 1,171 materials with 20 or more suppliers and a flash point on file, only 83 are below room temperature. Two papers: a 2023 review on how yeasts join acetyl-CoA to ethanol through alcohol acetyltransferase, and a 2003 analysis of eight freshly distilled Calvados finding that esters peak around 500 g per hectolitre of pure alcohol, a level that also corresponds to ethyl acetate's own threshold, so quality turns on the ratio of total esters to ethyl acetate. The same paper sniffed out 71 odours by GC-O: 18 marked defects and only 6 marked quality.
Material guide · 170 2026-05-24 21 min read Material guide: vanilla extract — 109 suppliers, and the odor field is one word long CAS 8047-24-3. This material's odor field reads vanilla. That is the whole field, one word. Of the 6,913 materials in this database with an odor field, 801 hold a single descriptor, and only five of those have more than 50 suppliers: vanilla extract at 109, peppermint oil at 88, rose specialty at 71, camphor at 66 and garlic oil at 53. They share one thing: the material's name is already the smell word. Once the name has said it, the odor field has nothing left to do. The flavor field on the same record holds seven words instead: vanilla, phenolic, balsamic, woody, spicy, floral, creamy. It was described as a flavour product. The refractive index is the giveaway: 1.340 to 1.390, where this database puts ethanol at 1.310 to 1.360 and clove bud oil at 1.527 to 1.535. That one field tells you most of the bottle is alcohol, and the notes field says so outright: the alcoholic solution of macerated vanilla planifolia. Shelf life is 6 months, the shortest common bracket. Two papers cover the same ground: stable isotopes of carbon and hydrogen separate Vanilla planifolia from V. tahitensis, and separate pods from C3 plants from petroleum.
Material guide · 171 2026-06-05 22 min read Material guide: juniper berry oil — the catalogue itself says most of what is sold is a distillery byproduct CAS 8012-91-7, 107 suppliers. The most important thing about this material is in none of the searchable fields. It lies in the middle of the free text of the notes: the best oil is steam distilled from crushed, dried or partially dried ripe berries, but the greater part of all commercial juniperberry oil is derived from fermented fruits as a byproduct of central European juniper brandy manufacturing. What you buy is usually not berries distilled to make a fragrance material, it is what was left after the spirit was made. The same notes field carries a stray fragment of a pharmacology abstract, minimizes hepatic reperfusion injury, which is evidence of how this catalogue was stitched together. Two more things: CAS 84603-69-0 covers 12 records spanning berry CO2 extract, needle oil, wood extract, fruit water, tincture and sprout extract; and two products named juniper lactone and juniper muscone share CAS 109-29-5 with an odor family of musk and 400 hours of longevity, so neither is juniper. Two papers: Bulgarian juniper berry oil runs 51.4% alpha-pinene, and two other Juniperus species share none of its main constituents, one of them carrying podophyllotoxin.
Material guide · 172 2026-06-09 22 min read Material guide: sulfurol — 27th in the database by supplier count, and no perfumer has heard of it CAS 137-00-8, 105 suppliers, with only 26 materials in the whole database carrying more. Yet its odor field reads fatty, cooked, beef juice, meaty, brothy, nutty, yeasty, bready, oily, sulfurous, and its odor family is meaty. This material lives in the flavour world, and a perfumer will never meet it. The notes field explains what it is in one line: the thiazole portion of thiamine. Vitamin B1 is a pyrimidine ring and a thiazole ring bridged together; cut off the thiazole half, hang an ethanol chain on it, and this is what you get. The occurrence list matches that origin, being entirely things that have been heated: roasted beef, beer, brandy, cocoa, cognac, roasted peanut, wine, with porcini and malt added by the notes. A 2003 University of Florida paper made the point cleanly: put 0.024 mM thiamin in model orange juice at 35 °C for eight weeks and 13 aroma-active components appear, two of them within days and accounting for 33% of total aroma activity by day seven, detected by nose before the instrument found them. The same chemistry is flavour in beef and spoilage in juice.
Material guide · 173 2026-06-21 21 min read Material guide: delta-decalactone — same molecular formula as gamma-decalactone, and the odor family field splits them anyway CAS 705-86-2, 104 suppliers. It shares a molecular formula with the gamma-decalactone already covered here, C10H18O2, and the same molecular weight of 170.25. The only difference is whether the ring has five members or six. The database's odor family field splits them regardless: gamma is fruity, delta is coconut. Line the series up from C8 to C12 and the delta column stays coconut throughout while the gamma column jumps to fruit at C10 and C12. Longevity does not follow ring size at all: delta-nonalactone records 24 hours while delta-octalactone, one carbon shorter, records 400. There is one interesting word in the natural occurrence list: margarine. And a 2022 Tokyo University of Marine Science paper is about exactly that. Measuring lactone enantiomer ratios in butter, fermented butter and margarine by enantioselective GC-MS, butter gave (R)-delta-decalactone while margarine gave only racemic forms, which the authors read as added synthetic aroma chemicals. A 1997 paper pulls it back, though: a yeast produces gamma-lactones at a fixed enantiomer ratio unaffected by the growth medium, and that too is a legal natural flavour. Enantiomer ratios are evidence, not a verdict.
Material guide · 174 2026-06-26 23 min read Material guide: trans-anethole — same molecular formula as methyl chavicol, the double bond one position over, and only one of them is genotoxic CAS 4180-23-8, 96 suppliers. The formula C10H12O maps to four records and four CAS numbers in this database: trans-anethole at 96 suppliers, estragole at 47, an unspecified-isomer anethol at 18, and cis-anethole at zero. Same formula, same molecular weight of 148.20, and the only difference is where the double bond sits on the side chain. That one position sends them into entirely different regulatory worlds. The 1999 FEMA Expert Panel assessment took a mechanism-based approach: trans-anethole's hepatotoxicity runs through the metabolite anethole epoxide, and since neither the parent nor the epoxide shows evidence of genotoxicity, the liver tumours seen in high-dose female rats were judged secondary to hepatotoxicity rather than genotoxic. Flavour intake of 54 micrograms per kilogram per day against a female rat NOAEL of 120 milligrams per kilogram per day leaves a margin of at least ten thousand fold. Estragole, one position away, is metabolised to a genotoxic 1'-sulfoxy metabolite. Two practical notes: the melting point is 21 to 23 °C, so it crystallises in the bottle when the room is cool, and the solubility field carries the line avoid iron drums. And the clouding when you add water has its own physics, mapped by a 2024 study of the ouzo ternary system.
Material guide · 175 2026-07-12 20 min read Material guide: 2,3,5-trimethylpyrazine — one of nine materials asking for 0.01% or less, and by far the easiest to buy CAS 14667-55-1, 99 suppliers. Its strength field reads high, evaluate at 0.01% or less, and of the 2,451 records in this database carrying a strength field, only nine land in that bracket. Most of the nine are specialist items: maple furanone at 67 suppliers, caramel furanone at 41, propyl mercaptan at 24, o-cresol at 13, and even denatonium benzoate, a bittering agent whose odor field is empty. Trimethylpyrazine's 99 suppliers make it the outlier on that list. The family disagrees with itself, too: 236 records carry pyrazine in the name, 87 of them have odor data, and the recommended dilutions for the eight best-supplied run from 0.01% to 10%. Stranger still, 2-acetylpyrazine is labelled very high and recommended at 0.10%, while this one is labelled high and recommended at 0.01%, so the adjective and the number point opposite ways. Two papers: a 2013 stable isotope dilution study quantified 12 alkylpyrazines in coffee, ranking this one seventh, with total alkylpyrazines in commercial ground coffee at 82.1 to 211.6 mg/kg and decaffeinated samples at 0.3 to 0.7 times regular; and a 2025 study heating 18 amino acids at 160 °C for an hour found pyrazines forming even without reducing sugars.
Material guide · 176 2026-07-24 20 min read Material guide: gamma-nonalactone — only three records in the database carry (so-called) in their name, and none of the three is an aldehyde CAS 104-61-0, 96 suppliers. Its catalogue name is gamma-nonalactone (aldehyde C-18 (so-called)). Of 42,225 records, only three carry so-called in the name, and all three tell the same lie: gamma-undecalactone wears aldehyde C-14, this one wears C-18, and strawberry glycidate wears C-16. None is an aldehyde, and none of the carbon counts matches either. This molecule has nine carbons, not eighteen. The proper-name field says it plainly: nonano-1,4-lactone. Better still, the demonstration accord sitting in its notes field uses three of those same fake aldehydes among its six components. The strength field reads medium with no concentration at all, making it one of the 1,649 records that give only an adjective. The literature does give numbers: a 2009 Australian study synthesised all eight enantiomers of four gamma-lactones and measured detection thresholds in red wine by ASTM E 679 with a 25-member panel, finding the lowest at 8 micrograms per litre for (R)-dodecalactone and the highest at 285 for (R)-nonalactone. Another paper found it in the headspace of freshly cooked white rice.
Material guide · 177 2026-07-28 19 min read Material guide: grapefruit oil — the word grapefruit does not appear in its odor field CAS 8016-20-4, 95 suppliers. The odor field reads dry, citrus, bitter, aldehydic, terpenic, fruity, tropical, orange. Eight words, and not one of them is grapefruit. The flavor field is a single word: grapefruit. The optical rotation explains why. At +91 to +96 that is the signature of limonene, which is most of what this oil is. The two trace components that actually make it smell of grapefruit sit in the database as separate items, and both are better supplied than you might expect: (+)-nootkatone has 104 suppliers, more than the oil's own 95, and grapefruit mercaptan has 64 with a strength field asking for 0.10% or less. A 2001 Munich study quantified 25 odour-active compounds in hand-squeezed grapefruit juice by stable isotope dilution and concluded that the typical sulfurous, grapefruit-like quality comes mainly from two thiols. In 2016 the same laboratory synthesised 34 derivatives for a structure-odour study, 18 of them reported for the first time, and recorded 1-p-menthene-8-thiol's odour threshold in air at 0.000034 ng/L, which they describe as among the lowest ever reported for a food odorant.
Material guide · 178 2026-08-13 20 min read Material guide: trans-2-hexenal — the database holds two records under this name, one with 91 suppliers and one with 2 CAS 6728-26-3, 91 suppliers. Search this material by name and you get two answers: one under CAS 6728-26-3 with 91 suppliers and twelve descriptors, and one under CAS 85761-70-2 with 2 suppliers and an odor field reading only green and leafy. Same name, same formula C6H10O, same molecular weight, and a 45-fold difference in supply. Its notes field warns of a second trap: do not confuse it with hexenal, a synonym for a barbiturate. Set beside the two green materials already covered here, this is the awkward one of the three. Leaf alcohol and its acetate are both recommended for evaluation at 10%; this one asks for 1%. Its flash point of 38.33 °C is the lowest of the three, its 12-month shelf life the shortest, and its vapour pressure of 4.624 is four times the other two. Two papers: a 2006 cucumber study established the mechanism, with a wounding-induced hydroperoxide lyase cleaving out C6 and C9 aldehydes, and the C9 aldehydes showing fungicidal activity against Botrytis and Fusarium at concentrations close to those in disrupted tissue; and an Italian study from the same year used trans-2-hexenal vapour against blue mould on pears, with residue after six days lower than the compound's natural content in unripe fruit.
Material guide · 179 2026-08-21 19 min read Material guide: black pepper oil — two touch words in its odor field, and the molecule that actually burns is not in the oil CAS 8006-82-4, 92 suppliers. Its odor field reads warm, spicy, terpenic, herbal, peppery, woody, pungent, and two of those, warm and pungent, are trigeminal sensations rather than smells. Across the 6,913 records with an odor field, 109 contain pungent, 124 warm, 96 cooling and 58 sharp, while burning, tingling, numbing and irritating appear zero times. The distribution does not match intuition: the best-supplied material with pungent in its odor field is leaf alcohol at 120 suppliers, and the best-supplied with cooling is geranyl acetate at 130, one a cut-grass note and the other a rose. Exactly one record carries both pungent and cooling. Black pepper's heat comes from piperine, which has four records in the database, only one of them with any odour data, and being non-volatile it does not survive distillation. A 2019 structural study showed piperine binds the same ligand pocket as capsaicin but in different poses. A 2004 study measured the composition of black, green and white pepper oils, where the drying method alone changed the oil yield of green pepper fifteenfold.
Material guide · 180 2026-08-25 18 min read Material guide: lemongrass oil — two species under one name, and West Indian lemongrass is not from the West Indies CAS 8007-02-1, 88 suppliers. Its systematic name field is not one name but two: cymbopogon citratus dc and cymbopogon flexuosus oil. The notes field spends a paragraph explaining why — lemongrass oil comes from two distinct Cymbopogon species, one native to the East Indies (C. flexuosus) and one, C. citratus, that the catalogue itself says carries the somewhat confusing name West Indian lemongrass. It is not from the West Indies; it was simply transplanted worldwide. Better still, the TSCA definition on the last line of that same paragraph names only one of the two species. A 2021 Egyptian paper measured one field across four seasons: oil yield ran from 0.15% in winter to 0.46% in spring, and GC-MS identified 61, 25, 50 and 63 components in spring, summer, autumn and winter — same grass, a 2.5-fold spread in component count. One more database detail: CAS 5392-40-5 holds two records, one for citral itself (135 suppliers, 12 hours substantivity) and one for terpeneless litsea cubeba oil (3 suppliers, 24 hours). Strip the terpenes and the catalogue considers it to be the compound.
Safety · 8 2026-04-26 23 min read The EU names 26 fragrance allergens; the database holds 23 of them, and two of the three missing were later banned Every so often a headline says a perfume was found to contain an EU-banned sensitiser. So I took the list of fragrance allergens that Annex III of the EU cosmetics regulation requires to be named on the label, and checked all 26 against this database one at a time. 23 are there, with 1,774 suppliers between them and geraniol the largest at 198. The three missing are HICC (Lyral), BMHCA (Lilial) and methyl 2-octynoate, and the first two are precisely the ones the EU later banned. A catalogue never marks a material as banned; it simply stops appearing, and absence is not a warning. Two more things: of the 23, only 13 carry skin sensitisation H317 in the GHS field, with linalool, coumarin and benzyl alcohol among those that do not, because a labelling list and a hazard classification are two lists with different purposes. And only 359 of the site's 42,225 records carry a GHS field at all, under 1%. Two papers: European data on 124,472 patients shows HICC allergy falling year on year before the ban took effect, and a 2024 systematic review puts fragrance mix I and II sensitisation at 6.81% and 3.64%.
Reading the data · 15 2026-04-10 21 min read One molecular formula, 217 materials under it, from rose to mushroom Someone searched the molecular formula C10H18O and landed on this site. So I went back to the database: 217 materials sit under that formula, 78 of them carry odor data, and those 78 are spread across 19 odor families. Geraniol for rose, 1,8-cineole for eucalyptus, menthone for mint, decenal that smells of coriander leaf and mushroom. Same formula, and all of them weigh 154.25. Longevity runs from 1 hour to 388, a 388-fold spread. Of the 21,610 materials with a usable formula field, 17,081 (79%) do not have that formula to themselves. This piece covers why a formula is almost useless as a search key, plus two papers: a 2000 Hiroshima study comparing the two enantiomers of linalool found differences not only in subjective impression but in forehead EEG, and the 2023 Science principal odor map predicted odor descriptors from molecular structure well enough to beat the median trained panelist. That model eats a structure graph, not a formula.
Reading the data · 16 2026-06-30 17 min read The strength field is not a threshold: 354 materials say high, and their recommended dilutions span a thousandfold Two ethyl esters in this database have almost the same supplier count: ethyl butyrate at 102 and ethyl 2-methyl butyrate at 104. The strength field separates them sharply, though. The first reads high, evaluate at 1% or less; the second reads medium, evaluate at 10% or less, a tenfold difference. The literature puts them the other way round. A 2016 stable isotope dilution study of mango named ethyl 2-methylbutanoate among the most potent compounds it found, with ethyl butanoate in the same group at an OAV of 980. A 2024 paper on ancient Chinese apple cultivars states directly that ethyl 2-methylbutyrate has an extremely low odour threshold. This is not a contradiction: the two fields answer different questions. Spread out all 2,451 records carrying a strength field and it becomes clear. 1,649 of them give no concentration at all, only an adjective, and of the 354 marked high the recommended dilution splits into 1% for 163, 10% for 145, 0.10% for 37, 5% for 4 and 0.01% for 3, a thousandfold range under one word. This piece covers what the strength field actually is, how it differs from an OAV, and how to use it.
Beginner perfumer · 4 2023-01-21 12 min read Use three materials for your first accord — this is not a beginner's limit Ten materials give you 120 possible trios, and you cannot tell any of them apart. Two studies, from 1989 and 1996, found that people identify at most three or four components in a mixture — and that training does not raise the ceiling. Professional perfumers included.
Beginner perfumer · 5 2023-01-25 15 min read Top, heart and base are not three stages — evaporation is one continuous curve Splitting a fragrance into top, heart and base is formula language, not physics. A 1995 headspace study showed evaporation as a continuous decay curve per ingredient; a 2025 study showed the same fragrance evaporates at different rates on different people's skin. Here is how to build a curve that does not collapse in the middle, using substantivity figures from 1,871 materials.
Beginner perfumer · 6 2023-01-29 16 min read IFRA limits the finished product, not the material — and when a beginner needs to care IFRA limits rest on a quantitative risk assessment for skin sensitisation, and they are set per product category — the same material has completely different ceilings in a candle and in a face cream. What the limits actually restrict, why they force structural changes to a formula, and when someone working only on smelling strips can ignore them.
Beginner perfumer · 7 2023-02-02 14 min read When you stop smelling anything: olfactory fatigue, and how many materials to evaluate at once Olfactory adaptation is stimulus-specific — you lose sensitivity to what you have been smelling, not to everything. And cross-adaptation tracks perceived similarity, not chemical structure. Two studies plus a descriptor-overlap analysis of 3,790 materials, and why switching nostrils does not help.
Beginner perfumer · 8 2023-02-06 20 min read What an evaluation note should contain — and why "smells nice" is not data The same odour, given a different label, gets the opposite hedonic rating — so "smells nice" records you on that day, not the material. Two studies plus a descriptor analysis of 5,824 materials: what makes a description stable, how many words it takes to identify a material, and what a note looks like that still reads six months later.
Beginner perfumer · 9 2023-02-10 20 min read The same name is not the same material: batch variation, and where natural and synthetic actually differ Wild rosemary from one hillside, varying only season and distillation method, ranged from 7.31% to 21.72% α-pinene. Commercial oils labelled Pinus sylvestris show the opposite enantiomeric excess from authentic ones. Why batches move, why the natural/synthetic line is about variance rather than chemistry, and what it means for your notes.
Beginner perfumer · 10 2023-02-14 20 min read Why a formula cannot be written in drops: weighing, percentages, and a 1% solution you can reproduce Across 192 pharmaceutical dropper bottles and 32 designs, drop volume ranged from 0.024 mL to 0.221 mL, and identical 5 mL bottles yielded between 111 and 209 drops. Among 3,863 liquid materials in our data, specific gravity runs from 0.706 to 1.560 — the same volume, twice the mass. Why formulae are written in percent by weight, how many decimal places your balance needs, and how to handle trace materials.
Beginner perfumer · 11 2023-02-18 21 min read A solvent is not a background: choosing between DPG, ethanol, IPM and TEC, and how it reorders what you smell DPG, IPM and TEC are all recorded with odour strength "none" — so "the solvent smells" is largely the wrong objection. The real effect is on release: ethanol changes mass transfer coefficients, and it does not shift the whole evaporation curve uniformly, it reorders which compounds arrive first. Plus: 763 materials carry an explicit recommended evaluation dilution, spanning 0.01% to 50%.
Beginner perfumer · 12 2023-02-22 19 min read A fixative does not hold anything down: why musks last, and why what lasts is not your formula Evaporation is governed by vapour-liquid equilibrium and activity coefficients, not by one molecule gripping another. Our data shows musk really is the most substantive family (53% at the top of the scale, the rest with a median of 336 hours against 53 overall) — so the first half of the advice is right. But at hour eight you are smelling the musk, not your composition. And a study of 530 people shows one receptor variant changes how strong your musk is in someone else's nose.
Beginner perfumer · 13 2023-02-26 23 min read Everyone's nose is different — so does "smells good" mean anything? Blind test design, and when one person's evaluation can be trusted Two people differ functionally at over 30% of their odorant receptor alleles. Yet across 235 people in 9 non-western cultures, molecular identity explained 41% of the variance in pleasantness rankings and culture only 6% — leaving the largest share to neither. How much consensus actually exists, how to run a blind test, and which questions one evaluator can and cannot answer.
Beginner perfumer · 14 2023-03-02 22 min read Formula cost and sourcing: the expensive material is rarely the problem — not being able to buy it is Cost is dose times price, so an expensive material at 0.5% often costs less than a cheap one at 40%. The real constraint is availability: of 21,494 materials with a supplier in our data, only 8.1% are carried by any small-quantity retailer, and only 26% of the 5,824 with odour descriptions. And 28% of materials have exactly one supplier in the whole database.
Beginner perfumer · 15 2023-03-06 22 min read The bottle you opened is no longer the same material: oxidation, storage, and whether refrigerating and decanting actually help Pure linalool showed no sensitising potential in the local lymph node assay; air-exposed linalool did, and the hydroperoxides were the strongest allergens. Among 5,511 consecutive patch-tested patients, 8.8% reacted to linalool hydroperoxides. In our data every material recommended for storage under nitrogen is an aldehyde or a terpene, and citrus and fruity materials carry half the recommended shelf life of other families.
Beginner perfumer · 16 2023-03-10 24 min read Joining fifteen articles into one path: from a new material to a formula you can hand over The close of the series. The previous fifteen articles each solved one problem; this one connects them into a workable process, and uses the data to size the realistic starting point — 42,225 materials filtered by supply, odour data, small-quantity availability and perfumery rather than flavour use leaves 1,244, or 2.95%. It ends with what this path can and cannot give you, including what the literature is still unsure about.
Beginner perfumer · 17 2024-01-02 25 min read You bought thirty materials and froze — stop buying and go look at which two turn up together Someone ordered thirty-odd materials in one go and got home with no idea what to do. I computed pairwise co-occurrence across 953 public formulas: after merging synonyms, eight clusters fall out of the 132 common materials. Two things surfaced along the way — my highest-lift pair turned out to be a spelling artifact, and 69% of the pairs that really co-occur are absent from the database's official blend suggestions, oakmoss with patchouli and bergamot with lavender among them.
Beginner perfumer · 18 2024-01-18 22 min read Do I need to know chemistry to start? No — but there is one piece of arithmetic you cannot skip Twenty-nine replies agreed: you don't need chemistry. They are right. But a single two-point reply named the thing that actually bites — you need to work out percentages to stay inside IFRA limits. I measured every pre-dilution row across 954 public formulas: 68% of them contain at least one row where the number on the sheet is ten times the actual material. And I made the same mistake twice while measuring it.
Beginner perfumer · 19 2024-01-26 24 min read How long does maceration need — and the 4.6% of water nobody in the thread spotted at first Someone asked whether it was normal for a perfume to smell weak and alcoholic four days after mixing. Most of the 43 replies said wait longer. Several rounds of questions later, the real problem surfaced: they had added 4.6% distilled water. I computed water solubility across the 53 starter palette materials — 47 have a figure, the median is 100 mg/L, and not one of them reaches 1%. As for maceration, a 1987 study measured the chemistry that happens over three months.
Beginner perfumer · 20 2024-02-03 26 min read Can you make perfume with just ethanol and essential oils — yes, and the molecules you were avoiding are still in the bottle Someone bought a batch of oils and absolutes and asked whether that makes a usable EDP. The 53 replies moved quickly from "can you" to "is what you bought real". I measured the natural content of 953 public formulas: a median of 4.5% by weight, 30% contain no naturals at all, and not one is entirely natural. More interesting still, ylang ylang oil is itself 35.49% linalool — the single most frequent material in the corpus.
Beginner perfumer · 21 2024-02-11 26 min read Loud on the blotter, gone two steps away — diffusion does not come from adding fixatives A forum thread argued it out: one side said diffusion comes from learning to work with fixatives, the other said fixatives in that sense are a myth. I ran the 1,319 database materials that carry both a vapour pressure and a longevity record. The log-log correlation is −0.625, and the quartile ladder is perfectly monotone: the most volatile quarter lasts a median of 4 hours, the least volatile 216. More telling still, the materials so potent they need diluting to 0.01% before you can evaluate them have the highest median vapour pressure of all.
Beginner perfumer · 22 2024-02-27 30 min read The most common beginner mistake: four materials in one slot A thread asked what beginners stumble over, and the most concrete answer in 31 replies was: four musks, three dry woody ambers and two hedione-types all in one formula. I went back to 954 public formulas and counted. Of the 410 that use a musk at all, 273 use exactly one, and only 9 use four or more — and not a single formula in the corpus stacks four musks alongside three ambers. The same data settles the argument over whether buying 1 g is a waste: both sides are right about different halves of the palette.
Beginner perfumer · 23 2024-03-07 28 min read Should you add glycerin: it is not useless, it is in the wrong product A thread listing beginner myths included "you need to add water, glycerin, etc", and a reply said nobody has ever claimed that — to which another reply said you have not hung around here enough. I counted: 3 of 91 posts in one week on that sub asked about it. The database answers more directly. Glycerin's odour field says odourless, its strength field says none, its longevity field is blank, and it is classified as a solvent rather than a fragrance material. Its logP is −1.80, against a median of +3.0 across 1,465 materials with longevity records.
Beginner perfumer · 24 2024-04-08 27 min read "Under eight hours means it's cheap": what that standard deletes at the material level A thread asking perfumers what annoys them drew 61 replies, and the biggest single answer was the same thing — being asked how long it lasts before anyone has smelled it. I took the eight-hour standard to the database. Of 2,027 materials with a longevity record, 15.6% last under eight hours, and their odour classes are fruity 68, green 60, herbal 35, citrus 24 — the entire top note register. More interesting is supplier count: across five longevity bands the averages are 25.0, 22.3, 20.7, 23.0, 21.1, which is a flat line. Longevity does not track how obtainable a material is.
Beginner perfumer · 25 2024-04-24 31 min read Which trials are worth keeping to see if they improve: a criterion you can look up Someone posted a lament about making the best perfume of their life and not writing the formula down. Two people in that thread asked the same question and nobody answered it: when a trial is not perfect now, how do you decide whether to keep it and wait? Keeping everything fills the shelf. I approached it through one specific reaction — anthranilates and aldehydes condense into Schiff bases in the bottle — and found that 102 of 954 formulas (10.7%) contain both classes, while 11 buy a ready-made Schiff base as an ingredient. A second question also went unanswered: can a lost formula be recovered by GC-MS?
Beginner perfumer · 26 2024-05-10 29 min read White particles in the bottle: eight incompatible explanations, and a test you can run yourself Someone posted a photo of white particles and a strand floating in their fragrance. Thirty replies gave at least eight mutually incompatible answers. Of the 460 materials in our database with 20+ suppliers and a recorded melting point, 255 (55.4%) are solid below 20 °C. Orris butter melts at 40-46 °C, copal at 90-140 °C. And the most confident answer in the thread used the wrong word: micelles need a surfactant, and fragrance formulas usually have none.
Beginner perfumer · 27 2024-05-18 31 min read His own control test lied to him for a year: a case of the wrong suspect Someone spent a year reformulating a perfume around salicylates, because he had run an isolation test and it confirmed his suspicion. Three strangers said it sounded like veramoss. He retested: the earlier test had been contaminated, and the salicylates ran 16 hours with no bitterness. The database explains why contamination runs one way — veramoss is rated high strength and lasts 400 hours at 10% dilution, while benzyl salicylate is rated low and lasts 384 hours neat. Across 954 formulas, high-strength materials sit at a median dose of 0.80% and low-strength at 5.78%. Also: no published formula uses Calone above 2.50%, and he used 25%.
Beginner perfumer · 28 2024-05-22 34 min read A supplier listed five jasmines. They aren't five origins — two of them contain no flower Someone was overwhelmed by a supplier's jasmine options and listed five names asking which was best. Nobody in the thread said the crucial thing: those five are not the same kind of product. The database holds 74 entries whose name contains 'jasmin', 52 with a supplier, and 9 whose occurrence field reads 'not found in nature'. Two product-line words work almost perfectly as labels: of the 28 supplier listings containing 'Floraline', not one maps to a real extract, and the same holds for the 52 containing 'Givco'. One commenter guessed Floraline was the grandiflorum version. It is a reconstitution.
Beginner perfumer · 29 2024-05-30 29 min read "I want an environmentally friendly, non-hormone-disrupting musk" — the honest answer is worse than it sounds Someone on a forum loves Galaxolide but wants an environmentally friendly, non-endocrine-disrupting replacement. Both reasons are checkable, and checking them does not produce a recommendation. The database holds 36 musk entries with ten or more suppliers, and 23 of them (64%) have no GHS field at all. Of the 13 that do, 8 carry an aquatic hazard, and all 8 are polycyclic or nitro musks. A 2023 global review stops in the same place: data on macrocyclic and alicyclic musks are limited for both occurrence and PBT properties. Two independent sources go silent at the same point, for the same reason.
Beginner perfumer · 30 2024-06-07 30 min read He asked whether one or two would do. The forum named forty Someone wanted to make an ocean fragrance dirtier and said plainly that he did not want to spend more than necessary. Thirty-six replies produced 42 material mentions, 40 distinct after merging duplicates. The median public formula holds 16 materials, of which 9 carry 90% of the weight and the top 3 carry 54.7%. Only 10.5% of formulas contain 30 or more materials. A 2012 PNAS study adds a ceiling: at about 30 equal-intensity components spanning odour space, most mixtures smell alike despite sharing no component. And one material in that thread got four different descriptions from four people, which is not anybody misremembering.
Beginner perfumer · 31 2024-06-15 27 min read "Workhorse" is measurable: a report card across fourteen genres of 954 formulas Someone asked which materials count as workhorses — "components like Hedione or IES, which can make composition better without being too obvious". That definition has two conditions, and both can be measured. I sorted 954 public formulas into fourteen genres by title, then counted how many genres each material appears in and how concentrated it is in its biggest one. Patchouli oil and bergaptene-reduced bergamot span all fourteen with only 19.9% and 20.2% in their largest genre. Hedione's floral share is 35.4%, exactly matching the corpus's own floral baseline of 35.4%. Fifteen of the forum's sixteen scoreable nominations hold up.
Beginner perfumer · 32 2024-06-23 28 min read Three habits when evaluating, two of which do nothing A thread asking what annoys perfumers drew 62 replies, and three checkable habits are buried in the complaints: sniffing the cap, resetting your nose with coffee beans, and judging in the first ten seconds. The coffee one has been tested — a 2011 study had participants sniff coffee beans, lemon slices or plain air after nine rounds of fragrance, and coffee did no better than the other two. A 2000 review explains why: olfactory adaptation is stimulus-specific and recovers with time and absence, not with a competing odour. For the third, the corpus says materials lasting under 24 hours make up 25.4% of the median formula's data-covered weight.
Beginner perfumer · 33 2024-07-01 29 min read "Add some Iso E Super and it'll last" — that material's substantivity is 172 hours, and it may already be in there A forum complaint: people keep believing they can add a few common materials to a mystery fragrance oil and transform its performance, and "it's always iso e super or ambroxan". The database gives Iso E Super a substantivity of 172 hours and a strength of medium — less than half of hexyl cinnamal's 400. It appears in 104 of 954 formulas (10.9%), and formulas containing it hold 14.2% of their weight in long-lasting materials against 14.1% for those without. Along the way, something nobody in the thread mentioned: this material has two environmental studies that reach opposite conclusions, with differently affiliated authors.
Beginner perfumer · 34 2024-07-09 24 min read Grading longevity from excellent to poor draws a line through a distribution that has no natural cut points A forum complaint blamed a fragrance database for rating longevity from excellent to poor instead of just showing the time with no value judgement. The data can be looked at. This site's database holds 2,027 substantivity records with only 210 distinct values, and twelve of those values account for 55.4% of all records. Worse, the values are round numbers — 4, 8, 12, 24, 400 — so a line at eight hours does not fall in a gap between groups. It cuts straight through the 92 records sitting on exactly 8.0. Survey methodology has long measured that labels change how people answer, though those studies measured respondents rather than readers.
Beginner perfumer · 35 2024-07-17 32 min read "I can't smell it" — five reasons, two of them arithmetic and one written in a gene Someone bought orris butter at 10% in TEC, found it thick and undetectable after thirty minutes, and had read that it was a base note. Twenty-one replies offered five explanations. The appearance question has a clean answer: orris butter melts at 40-46 °C and is solid at room temperature. The smelling question is arithmetic: his material was already a 10% product diluted to 1%, which is 0.1% orris butter — the most careful comment in the thread was off by more than tenfold. The database rates orris butter's strength as low. And two people in that thread report opposite experiences of beta-ionone, which is exactly the case where one genetic variant explains over 96% of the difference.
Beginner perfumer · 36 2024-07-25 30 min read Your scale decides how many materials your formula can have — on a 30 mg scale, 14 of 17 cannot be weighed Someone making their first perfume asked whether a scale with 30 mg readability is good enough. It can be worked out: at a 20 g batch and 1% weighing accuracy, 14 of the 17 materials in their formula fall short, and 10 still fall short at 5% accuracy. Swap in a 1 mg scale and 14 becomes 1. Across 954 public formulas, 24.6% of material entries sit below 1% and the median formula has 7 materials below 3%. Dilutions are not an advanced technique — they are what the scale forces on you, and they carry their own accumulating error.
Beginner perfumer · 37 2024-08-02 28 min read What does "sportiness" contain? — the word appears zero times across 42,225 materials Someone wanted to add a bit of sportiness to a perfume, and the shortest reply asked the sharpest question: "Adding 'sportiness'? What does 'sportiness' contain?" That can be checked. Scanning the odour field of all 42,225 materials in the database: sporty appears 0 times, and so do sexy, luxurious and confident, while green appears 1,616 times and woody 1,469. Perfume's marketing vocabulary and a material's descriptor vocabulary are two barely overlapping sets of words. And the thread performed the translation itself — somebody turned "more sporty" into four concrete moves.
Beginner perfumer · 38 2024-08-10 28 min read "My frankincense smells like sage" — your theory is right, and it is not what happened here Someone asked whether low-quality essential oils are more terpenic and citrusy, reasoning that a low-effort distillation only extracts the highly volatile molecules. That mechanism is real: a 2019 study measured hydrodistillation time and found longer runs lower the monoterpene share and raise the sesquiterpene share. But it is almost certainly not what happened to their frankincense. A 2022 study analysed 21 commercial frankincense oils and found six adulterated with synthetic limonene, three with synthetic octyl acetate, three with castor oil, and several contaminated with other Boswellia species. And octyl acetate's odour field reads green, earthy, mushroom, herbal — which is what they described.
Beginner perfumer · 39 2024-08-18 28 min read What thirty materials buy you — worked out against 954 published formulas A student in Japan asked r/DIYfragrance for the cheapest way into the hobby, since shipping from overseas alone runs to $50. The most concrete answer was buy about 30 materials and think hard about which ones. That advice can be checked. Against 954 published formulas, owning the 30 most-used materials covers 35.2% of the median formula's weight; in a 16-material formula you would hold 5 of them. But the same corpus says something else: of 2,381 distinct materials, 1,065 appear in exactly one formula, and all the materials appearing in two formulas or fewer add up to a median 3.3% of a formula's weight. The tail is long and light.
Beginner perfumer · 40 2024-08-27 30 min read I run a nursery — can I grow my own perfume? The bottleneck isn't the flowers, it's the 95% Someone running a plant nursery asked r/DIYfragrance whether they could make perfume from plants they grew. The top reply said 100 kg of lavender flowers yields 0.5 to 1.5 kg of essential oil. That figure holds up: a 2022 study measured 1.2% yield for lavender at 100 minutes of hydro/steam distillation, and a 2021 study measured 2.0 to 3.8% for lavandin. But converted into one 50 mL bottle of perfume, the flowers needed come to 35 grams — one lavender plant covers it. The real bottleneck is elsewhere. Across 954 published formulas, the median formula is 95.1% single chemicals by weight, distillable essential oils account for 3.5%, and 312 formulas contain no essential oil at all.
Beginner perfumer · 41 2024-09-04 30 min read "This material won't dissolve" — why you can't look up whether it arrives as a solid Someone on r/DIYfragrance complained about crushing chunks of Tonalide and stirring until their arms ached, then asked what the hardest material anyone had worked with was. Thirty-one replies produced a list of a dozen. What makes the thread interesting is that what these people are trading is information the database cannot give them. Of the 120 most-used materials in the corpus, 41 have no appearance field in this site's database and 91 have no melting point. Across all 42,225 records, only 3,080 (7.3%) carry a melting point, and of the 10,270 with an appearance value, 10,248 (99.8%) are marked as estimates. The 41 that came back empty are a tidy list of trade names.
Beginner perfumer · 42 2024-09-12 32 min read Adding things to a finished perfume — addition is cheap, subtraction is nearly impossible Someone on r/DIYfragrance saw a fragrance described as close to Terre d'Hermès without the sportiness and thought they could just add some sportiness themselves. The most practical reply advised increasing the bergamot and lily of the valley materials and slightly reducing the patchouli and Atlas cedar. Two of those four instructions can be done and two cannot. Raising bergamot from the corpus median of 10.85% to 15% in a 50 mL EDP takes 0.46 g. Cutting patchouli from 8% to 4% means adding 9.5 g of everything-else, which doubles the concentrate — that is not a modification, it is a second perfume. And another reply saying this only works on classic colognes is supported by the corpus: citrus and cologne formulas have the lowest median effective material count of any genre, at 6.5.
Beginner perfumer · 43 2024-09-20 35 min read "Has my orris butter gone bad?" — the problem isn't the material, it's evaluating everything at 1% Someone posted a photo of their orris butter on r/DIYfragrance saying it looked too thick and vanished after 30 minutes, and wondering whether they had been sold a spoiled material. Neither suspicion survives checking. The database gives orris butter a melting point of 40 to 46 °C and an appearance of paste to solid, and a 2018 GC-MS analysis explains why: the rhizome oil is 56% myristic acid, 15.42% lauric acid and 14.50% capric acid — 86% fatty acids. The TEC they suspected of being thick melts at −46 °C. The real problem is in a line they wrote in passing: they evaluate every material at 1%. Of the 802 database records that carry a recommended evaluation strength, 527 say 10%, 204 say 1% and 45 say 0.1%. Of the 120 most-used materials in the corpus, only 6 should be smelled at 1%.
Beginner perfumer · 44 2024-09-28 36 min read Someone on a forum gave you a formula — run these four checks first Someone on r/DIYfragrance wanted a clean, light, modern white suede, saying Suederal LT reads too much like a handbag and Safraleine's saffron-medicinal side takes over. A reply supplied a complete 13-material formula summing to 1000. That formula can be checked, and the checking turns out to be more useful than the formula. First: three materials are listed as dilutions, and the IBQ marked "1%" is actually 0.01% — off by 97×. Second: Hedione at 22.75% and Iso E Super at 20.68% are both three times the corpus median — the lightness is not built by using less leather, it is built by overdosing the transparent materials. Third: Suederal, which gives the formula its identity, appears zero times across 954 published formulas. Fourth: three people say ionones soften leather, and with only 9 leather formulas in the corpus, that question cannot be answered.
Beginner perfumer · 45 2024-10-06 33 min read What's in a peach and what it takes to build one are two different lists A newcomer on r/DIYfragrance asked how to build peach. The top reply gave a list and a mechanism: C14 matters most, and fruit accords usually need green materials. Both are checkable. The database holds 160 materials whose natural occurrence field says peach fruit, and ranking them by supplier count puts seven lactones in the top twenty-five. Of the corpus's 122 fruity formulas, 61% contain a green material against a baseline of 37%. But the same figures produce a reversal: linalool has 558 natural sources, the third most widespread molecule in the database, and its rate in fruity formulas is 0.81× the baseline — below average. And a 2020 paper reports that the greatest contributor to characteristic peach aroma is γ-decalactone, while perfumery reaches for γ-undecalactone.
Beginner perfumer · 46 2024-10-14 29 min read Someone posted a 36-line crème brûlée formula, and half of it is solvent Someone on r/DIYfragrance posted their crème brûlée formula in French: 36 lines, totalling 1000. Multiplying every line's dilution strength back out gives 503.6 parts of neat fragrance material and 496.4 parts of solvent. TEC accounts for 405 of that, 280 written as a line of the formula and another 125 carried in by the 10% dilutions. That is not a flaw; it is why the formula can be built at all. Its smallest line is 5 parts of a 1% maple lactone, which converts to 0.05 parts neat, five parts in a hundred thousand of the formula. Weighing that neat to a 10% precision needs a 200 g batch; weighing the pre-made dilution needs 10 g.
Beginner perfumer · 47 2024-10-22 28 min read "I spilled sotolon on my fingers and my taste went off" — first separate taste from smell Someone on r/DIYfragrance spilled sotolon on ungloved fingers, and their sense of taste went off that same evening — described as their tongue wearing a condom, at about 80% sensitivity. One reply gets to the point: taste and flavour are not the same thing. The tongue handles salt, sweet, sour, bitter and umami; the lemon part is retronasal olfaction. A 2014 review supplies direct evidence: people with congenital anosmia have lower taste and trigeminal sensitivity. Another reply says sotolon gets into you and makes you smell of curry for days, which the US National Institutes of Health database states plainly, urine, sweat and faeces included. And sotolon's strength has coordinates: of 42,225 database records, it is one of nine recommended for evaluation at 0.01% or less.
Beginner perfumer · 48 2024-10-30 26 min read "RIP Lyral" — a third of these 954 published formulas cannot be made today Someone on r/DIYfragrance wants to build a clean, luxe, abstract perfume mainly from white musks. Another replies that musks alone will not get you clean; you need muguet materials. And at the end of the thread someone posts three words: RIP Lyral. That line can be counted. Of 954 published formulas, 331 (34.7%) contain at least one material now banned or severely restricted in the EU, and within those formulas the affected materials account for a median 5.82% of the weight — not trace decoration. And it is the same point as the earlier reply: the two materials that were banned, Lilial and Lyral, were both muguet materials.
Beginner perfumer · 49 2024-11-07 25 min read How strong should my ethanol be — reading "1:1.5 in 50% alcohol" in the database Someone on r/DIYfragrance asked how to read "ethyl alcohol, 1:1.5 in 50% alcohol" in benzyl alcohol's record. One reply got it right: make a 50% water-ethanol solution and one part of material dissolves in 1.5 parts of that. The notation is worth taking seriously, because there is real data buried in it. Of 42,225 database records, only 7 materials leave two or more measurements at different ethanol strengths, and the slopes of those seven curves differ enormously: vanillin moves 1.5-fold between 70% and 95%, benzyl benzoate moves 1000-fold between 45% and 95%. Plot the seven materials' logP against their slopes and the correlation is 0.876.
Beginner perfumer · 50 2024-11-15 27 min read 190 proof or 200 proof — the argument is about the flattest part of the curve Someone on r/DIYfragrance ordered SDA 40B, received 200 proof, and asked whether they had messed up. The thread's consensus is that there is no difference and that 200 proof will absorb water down to about 191 on its own. Both hold up: 190 proof sits near the ethanol-water azeotrope, reaching 200 proof takes an extra process step and therefore costs more, and ethanol is hygroscopic by nature. But put the question against actual solubility data and the picture sharpens. Among the only seven materials in the whole database with multiple ethanol-strength measurements, benzyl benzoate needs 1:2 at 90% and 1:1 at 95% — a twofold difference. The same material needs 1:1000 at 45%. Benzyl acetate moves fortyfold between 30% and 60%. The forum is arguing about the flattest part of the curve, while the steep part sits at the finished product's fragrance load, where nobody is asking.
Beginner perfumer · 51 2024-11-23 30 min read Why won't maltol dissolve — 39 replies ranging from 1% to 10%, and nobody mentioned melting point Someone on r/DIYfragrance asked why maltol would not dissolve in 200 proof ethanol. Thirty-nine replies gave workable concentrations from 1% to 10%, contradicting each other. The contradiction has two sources and the database resolves both. First, half the replies are about ethyl maltol: the database gives ethyl maltol's solubility as 12% in alcohol, 10% in benzyl alcohol and 5.5% in propylene glycol, while maltol gets 2.8% in propylene glycol, 1.2% in glycerin, and no figure at all for alcohol. Second, nobody mentioned melting point: maltol melts at 159 to 162 °C and ethyl maltol at 89 to 93 °C, seventy degrees apart. Put both into Yalkowsky's General Solubility Equation and the predicted solubility ratio is 2.19×, against 2.22× from the database's own numbers.
Beginner perfumer · 52 2024-12-01 30 min read Is Cetalox the same as Ambroxan? The chemical registry says no, food-flavour regulation says yes This question has been asked at least three times on r/DIYfragrance, and 23 replies never settled it. Checking the registry numbers shows why: the answer depends on which body you ask. CAS assigns two numbers (6790-58-5 and 3738-00-9), yet the PubChem IUPAC names are identical except for one stereodescriptor prefix at the front. FEMA assigns both the same number, 3471; the Council of Europe assigns both 10514. The melting ranges agree with that reading: the stereochemically specified one melts over 74-75 C, the unspecified one over 75-85 C. Whether you can smell any difference is a separate question. Laska 1999 tested ten enantiomer pairs and found only three could be told apart, and a 2025 Communications Biology paper identified the receptor for this molecule, OR7A17, whose loss-of-function alleles are especially common in East Asia.
Beginner perfumer · 53 2024-12-09 25 min read Sprayer clogging: DPG or IPM? In 30 replies, most people were solving a different problem Somebody on r/DIYfragrance asked why their homemade Molecule 02 (ambroxan in alcohol, nothing else) keeps growing crystals that block the sprayer. Nearly all 30 replies said dilute it more. He wrote twice that nothing is crystallising in the bottle, only the nozzle drying out and clogging. One person asked which of the two it was, then wrote the most useful line in the thread: everybody is solving the other problem. The two have opposite fixes. Bottle crystallisation is cured by lowering the concentration; nozzle clogging is not, because once the ethanol evaporates the residue on the nozzle is 100 percent ambroxan whatever the bottle held. What you choose is a co-solvent that stays behind, and the field that decides that is vapour pressure. Lined up from the database, DPG turns out to be 3.5 times more volatile than ambroxan itself.
Beginner perfumer · 54 2024-12-17 24 min read Is Rose Oxide 70 worth the international shipping? Converting 5 percentage points into what you actually lose Somebody posted a precisely framed question on r/DIYfragrance: the formula calls for Rose Oxide 70 (cis:trans 70:30), the material generally on sale is 75:25, both carry CAS 16409-43-1, and the 70:30 version means paying overseas shipping and import duty. All 10 replies said it makes no difference under 1 percent, and nobody converted those 5 points into a quantity. It works out to 6.7 percent less cis, and it stays 6.7 percent whether you dose at 0.5 or at 2 percent. The side question about how one CAS can cover two materials has its answer written in the database's assay field: 99 to 100, sum of isomers. And the same set of records holds something more worth looking at: the substantivity field for one molecule reads 8 hours in one record and 388 hours in another.
Beginner perfumer · 55 2024-12-25 21 min read What percentage is three drops in 10 mL? And why 89% of the corpus looks over the limit Somebody on r/DIYfragrance made a wedding perfume out of ylang ylang essential oil and asked whether we overcomplicate things. A reply pointed out that ylang is limited to 0.73 percent of a finished product, and thirty-odd comments of arguing about whether to trust safety guidance followed. The poster stated the actual recipe twice, three drops in 10 mL of alcohol, and nobody converted it. It comes to between 1.09 and 2.17 percent, with the whole range above the line. The body oil they also made runs 0.62 to 1.23 percent, with the line through the middle. The third number is the one worth explaining: in our corpus of 954 formulas the median ylang dose is 2.5 percent and 89 percent of uses exceed 0.73, and those formulas are not in breach.
Beginner perfumer · 56 2025-01-02 28 min read Pyrazine vs pyridine: he said Google only tells him the structures, not how that relates to fragrance Somebody on r/DIYfragrance wanted Maillard-reaction aroma chemicals and got lost between acetyl pyridine and acetyl pyrazine, plus pyrroline, pyrimidine and pyridazine. He put it plainly: Googling will only tell me the differences in molecular structure, but not how that relates to fragrance. All seven replies said buy both and smell them, and nobody in the thread had ever used a pyridine. The database can answer this. The bare rings already diverge: the pyrazine ring on its own is nutty, roasted and hazelnut, while the pyridine ring on its own is sour, fishy and ammoniacal. And a 2001 paper used a neural network to sort 98 pyrazines into three aroma classes from structure alone at 93.7 percent accuracy. The relationship he wanted exists and has been quantified.
Beginner perfumer · 57 2025-01-10 21 min read How much does a natural actually vary? Measuring 'you never know where your lot falls' The biggest thread on r/DIYfragrance this month, 97 replies, argued about whether naturals or synthetics are safer. One reply came from somebody whose day job is toxicology research, and it made a different claim from everybody else: the problem with naturals is not toxicity but that you do not know the concentration of the active component in your lot. That claim is measurable. Taking the 1,800 database records that carry content percentages, I extracted 806 combinations of one molecule across at least three named origins of one botanical. The median spread is 7.1-fold, more than four in ten exceed tenfold, and the largest is 1,985-fold. Linalyl acetate in lavender oil runs from 0.1 to 34.69 percent. And eugenol in bay leaf runs from 0.1 to 68.93 percent, which is an individually restricted constituent.
Beginner perfumer · 58 2025-01-18 21 min read What are you smelling when you sniff the cap? The corpus's top 36 materials span 83,333-fold in volatility Somebody on r/DIYfragrance complained that when they hand over a tester, people pull the cap off and sniff the atomiser as if that tells them everything. A reply added that all you smell there is the dried-up juice. That is correct, and it is measurable. Matching the most-used materials in a 954-formula corpus against the database's vapour pressure field, the 36 that matched run from para-anisaldehyde at 1.0 mmHg down to musk ketone at 0.000012, a spread of 83,333-fold across 4.9 orders of magnitude. What survives after the ethanol goes comes from the bottom of that list, and that band accounts for 0 percent of the mass in half of all formulas. The cap does not give you a small version of the perfume; it gives you a badly skewed sample.
Beginner perfumer · 59 2025-01-26 24 min read What are the -olides? The suffix turns out to fail in both directions Somebody on r/DIYfragrance asked whether galaxolide, ambrettolide, helvetolide and exaltolide are a class, and where to find a breakdown of them side by side. Twelve replies produced three contradictory answers, one of which hit the point: -olide usually means a cyclic ester, but galaxolide and helvetolide are not cyclic esters, don't ask why. He was right, and the proof takes one line of arithmetic. Galaxolide's formula is C18H26O, one oxygen, and an ester needs two. As for whether the suffix works as a classification, the database answers in both directions: of 143 records containing olide, only 44 percent of those with an odour type are musks, and of 88 musk-type materials only 8 percent have olide in the name.
Beginner perfumer · 60 2025-02-04 24 min read What is the material that smells 'fuzzy, static-y, warm'? My database could not answer; the forum did in three hours Somebody on r/DIYfragrance asked for a material that smells warm, fuzzy and static-y, adding that it is like a vanilla bean and an unscented dryer sheet having a baby. Five replies gave five materials within three hours. I put the same question to my own database and it failed: of 169 controlled odour types across the library, not one names a texture, a temperature or a feeling; all 169 name a source or a substance. And the word static appears zero times in any field of 42,225 records. The papers side with the asker, though: a 2022 study predicting crossmodal correspondences from an electronic nose found texture smoothness the strongest of all dimensions at r = 0.82, ahead of colour and of pleasantness. And he had handed over a searchable term without noticing. I also got the Cashmeran row wrong on the first pass; the free-text field carries IFF's own words, powdery velvet nuance.
Beginner perfumer · 61 2025-02-12 17 min read Twelve replies about tape and boxes, and nobody mentioned what is inside the bottle Somebody on r/DIYfragrance was about to post their first homemade perfumes and asked how to package them. All 12 replies covered how to wind teflon tape, whether electrical tape looks tacky, and how to do box-in-a-box. Every one of them is physical protection. Not one mentions that what is in the bottle is a flammable liquid. Ethanol's flash point is 9.44 C, so an alcoholic perfume is under that line before you add anything. The aroma materials are not all safe either: of the 13,166 library records whose flash point parses in Celsius, 9.9 percent sit below 23 C and 13.0 percent between 23 and 60, which is close to a quarter between them. And the GHS hazard field cannot help, because only 369 of 42,225 records have one.
Beginner perfumer · 62 2025-02-20 18 min read What does '1:1.5 in 50% alcohol' mean? That field has a whole curve in it Somebody on r/DIYfragrance asked how to read benzyl alcohol's solubility field, which says ethyl alcohol, 1:1.5 in 50% alcohol, and why it specifies ethyl alcohol rather than just alcohol as it usually does. Two replies: one said the site is just weird sometimes, and one got it right. The answer is one part material in 1.5 parts of a 50 percent ethanol-in-water mixture. What he did not ask about is more useful: benzyl acetate's field carries five figures, running from 1:200 at 30 percent alcohol to 1:5 at 60. Fitting those five points to the log-linear cosolvency model gives an R squared of 0.9968.
Beginner perfumer · 63 2025-02-28 22 min read "Rename Pretty Oud to Shitty Oud" — the eight people arguing are not arguing about the same thing Somebody on r/DIYfragrance complained that Firmenich's Pretty Oud is marketed as a gentle oud with no animalic facets and is in fact the most faecal-smelling thing they have encountered. Five of the eight replies disagreed, and one of them supplied the key: he had exactly the same experience neat, and at 1 percent it became pretty. I checked whether Pretty Oud is in the database. It is, filed under agarwood specialty, with no CAS number and an occurrence field reading not found in nature. That record has 41 suppliers; the record for actual agarwood oil has 26. Adding the 16 for the replacer, more than twice as many suppliers sell an oud-shaped thing as sell oud.
Beginner perfumer · 64 2025-03-08 18 min read The material he asked about is not in a 42,225-record database, and there are four ways that happens Somebody on r/DIYfragrance asked about Orionide Oliffac, a new white musk base IFF had just shown at SIMPPAR2026. Among the 15 replies: this material does not seem to be available anywhere to buy yet, one supplier appears to be carrying it, and it is said to be based on IFF's new musk Luminide. I checked. Orionide is not in the database, and neither is Luminide. So I took all 46 trade names I have collected from fifteen rounds of reading this board and matched them at once. Four outcomes: 31 hit the name fields directly, 1 needed a spelling variant, 9 exist only inside supplier text, and 5 are simply absent. Not finding something is not one thing; it is four, and they need different fixes.
Beginner perfumer · 65 2025-03-16 25 min read Should I add BHT? "It probably doesn't do any harm" is checkable Somebody on r/DIYfragrance asked whether discolouration and degradation from oxidation are worth caring about, and offered four options: add it to dilutions, add it at maceration, it depends, or relax and decant into amber bottles. Seven replies disagreed with each other. The most useful one separated two problems: he adds BHT to stop things going rancid rather than to stop discolouration, and he actually likes it when they darken. Another said he uses both BHT and vitamin E, was asked why, and answered that there was no reason and it probably does no harm. That sentence is checkable. BHT has an odour type in the database, phenolic and camphoreous, a substantivity of 400 hours, and a single GHS statement that it is very toxic to aquatic life.
Beginner perfumer · 66 2025-04-25 20 min read Five people diagnosed the same formula and none of them named the two biggest ingredients Someone posted a 14-material formula asking why their perfume was not strong enough. All five replies said versions of the same thing: too much orris, too much Javanol and Amber Xtreme, not enough top notes, unbalanced, it will turn into mud. I ran the arithmetic. After backing out the solvent carried in by two 10% dilutions, the actual aroma material is 3.161 g and the finished concentration is 19.38%. Sorted by weight, the largest item is Iso E Super at 31.6% of the aroma material, followed by Grojsman Plus at 19.8% — neither was mentioned by anyone. The orris named as "100% the reason" ranks fifth at 8.6%. And two of the top three read `medium` in the strength field.
Beginner perfumer · 67 2025-07-23 18 min read "Add benzophenone for UV protection" — that word covers two different things, and the one you would buy has a smell A comment on the BHT article asked the follow-up: fine for oxidation, but what about UV — should I add benzophenone? I looked it up. The record named benzophenone (CAS 119-61-9, 41 suppliers) is categorised as a fragrance agent, with an odour field reading balsamic, rose, metallic, powdery, geranium, medium strength and 394 hours substantivity. The sunscreen ingredients are the benzophenone-3 (oxybenzone, 131-57-7) family — different CAS numbers, different records. Of the 45 materials classified as UV absorbers, none has an odour type. Worse, the database's own notes field says benzophenone is a classic photosensitizer with a near-100% triplet yield that abstracts hydrogen to form radicals — the opposite job from absorbing UV and dumping it as heat.
Beginner perfumer · 68 2025-07-27 14 min read How do you tell a material has been retired — the database has two fields for it, and they overlap on 18 records When you look up an obscure material, what you want to know is whether it can still be used. This database answers in two places: the category field can read "information only not used for fragrances or flavors", and the cosmetic_uses field can read "not used anymore". The first covers 6,457 records (15.3% of the database); the second covers 80. Both appear together on 18. Worse, of those 80 "not used anymore" records, 62 still carry a flavour or fragrance category. Dihydrocoumarin has 55 suppliers, allyl isothiocyanate 53, costus root oil 21 — all of them wearing both contradictory labels at once.
Beginner perfumer · 69 2025-07-31 12 min read Those 80 "not used anymore" materials split into two piles when you sort by FEMA number Last time I compared the cosmetic_uses field's "not used anymore" against the category field and called the two fields contradictory. That was imprecise. I ran one more check: do those 80 records still have a FEMA number? Twenty-six do (32%), with the regulatory field still listing JECFA, FEMA GRAS, CoE and FLAVIS — materials that left cosmetics while remaining legal flavour ingredients, and dihydrocoumarin with its 55 suppliers is in that pile. Fifty-four do not, and that pile reads: chloroform, 1,2-dichloroethane, dibutyl phthalate, diethylene glycol, hexane, safrole, psoralen, naphthalene, catechol, cobalt sulfate, and three nitro musks. This cut is far sharper than looking at category.
Beginner perfumer · 70 2025-08-04 13 min read The database has 178 "replacers", and most of them are not replacing something you cannot buy There are 178 records with "replacer" in the name, 144 of them with suppliers, and 87 that match a same-named original. The intuitive story is that replacers exist because the original is banned or unavailable. Across these 87 pairs that story almost never holds: only 3 originals are flagged "not used anymore" (dihydrocoumarin, costus root oil, musk ambrette), and only 3 replacers have more suppliers than their original. Meanwhile patchouli oil, with 148 suppliers, still has a 21-supplier replacer; lavender oil is 99 against 21, grapefruit 95 against 12, lemon 74 against 31. The one case where a replacer genuinely beats its original is civet absolute, 17 against 31.
Beginner perfumer · 71 2025-08-08 14 min read Only 11 records in the database are genuine animal materials, and their replacers have more suppliers Customs tariff heading 0510 is the one for ambergris, castoreum, civet and musk. Of the 42,225 materials in this database, 11 carry it. Their supplier counts add up to 61; the corresponding replacers add up to 80. Item by item it is sharper: civet absolute 17 against a replacer at 31, ambergris tincture 8 against "ambergris specialty" at 26, castoreum absolute 23 against a replacer at 19. And real deer musk — musk tonquin and musk tonquin absolute — has zero suppliers on both records. A 2014 Neuron paper also gives you a reason not to treat substitution as a neutral move: macrocyclic ketone, nitro, polycyclic and ester musks activate different glomeruli.
Beginner perfumer · 72 2025-08-12 14 min read "There's castoreum in your vanilla ice cream" — half of that is true, and the wrong half can be checked in the odour field This is one of the most widely circulated fragrance legends: vanilla-flavoured food really contains something squeezed out of a beaver's glands. It can be checked. The true half: castoreum extract is a registered flavour material, FEMA 2261, and Burdock's 2007 safety assessment says it has been added to food as a flavour ingredient for at least 80 years. The wrong half: of the eight castoreum records in the database, not one has the word vanilla anywhere in its odour, flavour or description fields. They read leathery, smoky, animal, phenolic, old wood, burnt. Castoreum absolute and vanillin share exactly one descriptor — phenolic — and that is a chemical-family word, not a tastes-like word. For scale: vanillin has 193 suppliers; all eight castoreum records together have 60.
Beginner perfumer · 73 2025-08-16 13 min read A third of the records sharing a CAS number are filed under different odour types A CAS number gets used as a guarantee that two things are the same substance. For naturals it is not. Records with an odour type in this database spread across 4,536 CAS numbers, of which 357 carry more than one record — and in 127 of those 357 groups (35.6%) the records are filed under different odour types. It is not random either: lavender shares CAS 8000-28-0, where the oil is floral and the absolute and concrete are herbal; lemon shares 8008-56-8, where sixteen of seventeen records are citrus and "lemon oil distilled" is floral; labdanum and cistus share 8016-26-0, where labdanum absolute is amber and cistus twig/leaf absolute is woody. One plant, different extractions, one number.
Beginner perfumer · 74 2025-08-20 14 min read Forty-six records have a notes field that says "do not use on any part of the body" — and bergamot oil and jasmine absolute are on the list The sentence hides in the notes field: free text, in a column nobody searches. I swept the whole database and found 46 records carrying that instruction. There are only two reasons given — phototoxic or sensitizing. The list includes cumin seed oil with 65 suppliers, bergamot oil with 58, angelica root oil with 46, tagete oil with 35, jasmin absolute (India) with 34, treemoss absolute with 29, costus root oil with 21 and Peru balsam resinoid with 20. These are not obscure materials. What to watch is that the sentence is blunt: it gives no limit, IFRA restricts rather than prohibits bergamot, and furocoumarin-free versions exist. De Groot's 2016 review notes that contact allergy has been described for 80 essential oils.
Beginner perfumer · 75 2025-08-24 16 min read An oil and an absolute are not the same material — three things measured across 50 pairs Fifty plants in this database have both an "X oil" and an "X absolute" record with suppliers on each. Line them up and the database gives three consistent directions. One, odour type: 45 pairs have a value on both sides and 14 disagree (31%), with a predictable direction — frankincense goes terpenic to balsamic, lavandin floral to herbal, geranium floral to green. Two, the strength field: 7 pairs have both, 4 disagree, and in all four the absolute is one step lower with no exception. Three, substantivity: 6 pairs have both, two absolutes are longer (galbanum goes from 72 hours to 400), four are identical, none is shorter. Supplier totals are 2,287 for the oils against 534 for the absolutes.
Beginner perfumer · 76 2025-08-28 13 min read Who wrote the odour field — a quarter of the 8,298 odour descriptions carry one of two names This database holds 8,298 records with an odour description, and 2,102 of them (25.3%) are signed by either Luebke or Mosciano. Luebke appears on 1,712 records with dates from 1981 to 2021; Mosciano appears on 928 and stops at 2001. More striking is how differently the two recorded their work: 99.2% of Luebke's 1,719 passages state an evaluation concentration, against 26.2% of Mosciano's 928. For solvent it is 36.9% against 1.3%. So when two descriptions look contradictory, the first move is not to decide who is right — it is to check whether a concentration is stated.
Beginner perfumer · 77 2025-09-01 11 min read How wide is the assay window — 86 of 1,794 materials have ends more than ten points apart The assay field rarely gives one number. It gives a range like "95.00 to 100.00", and that range is how much two bottles under the same name can differ. I measured the width across 1,794 materials with ten or more suppliers whose assay is written as a plain low-to-high: five points is commonest at 30.9%, then two points at 24.4% and one point at 17.1%. Eighty-six records (4.8%) are ten points or wider, and they include materials you actually use — beta-caryophyllene at 61 suppliers reads 80 to 100, rhodinol at 41 reads 70 to 100, camphene at 39 reads 80 to 100, pine oil at 38 reads 80 to 100. Three distinct causes are visible in the data, and they mean different things for you.
Beginner perfumer · 78 2025-09-05 12 min read Which grade did you buy — alpha-terpineol has five, and three of them are not numbers Last time I measured how wide the assay range is. This time I measure what sits upstream of it: the grade. Only 726 records in the database have anything in the formulations field (1.7% of 42,225), but those 726 all say the same kind of thing — how many grades exist under one name. Alpha-terpineol, with 103 suppliers, lists five: technical, perfumery, extra, prime, food chemical codex. Butyric acid at 75 suppliers lists eight. Ethanol at 41 lists seven. And these grade names fall into three kinds, only one of which gives you a number: purity percentages, pharmacopoeia or codex standards (USP/NF/FCC), and trade words with no defined content (extra, prime, perfumery, technical). The third kind is the commonest.
Beginner perfumer · 79 2025-09-09 10 min read The official blending list is truncated — capped at 120, and 55.5% of materials sit exactly at the cap The database's blending suggestions run to 673,662 rows, which looks like a complete relationship map. It is not. Each material's suggestions split into odour and flavour, each capped at 60, for a total ceiling of 120 — and of the 7,129 materials with suggestions, 3,957 (55.5%) stop exactly at 120, with none above it. So for more than half of all materials you are seeing a truncated top sixty, and nothing in the data tells you what was cut. That also explains two other things: of the 344,065 directed pairs that map back to material IDs, only 18.9% are mutual; and the 69% of empirically co-occurring pairs I previously found absent from the official list.
Beginner perfumer · 80 2025-09-13 9 min read 73.6% of the database's blending suggestions cross odour families, and a quarter of them point at floral Last time I measured that the suggestion list is truncated at 60 per kind. This time I measure its direction. Matching the source material's odour type against the suggested material's group, only 26.4% of 295,387 pairs stay within one odour type and 73.6% cross — so it is not a like-with-like list. But it is not neutral either: of 331,821 grouped suggestions, 80,697 (24.3%) point at floral, twice the share of second-place balsamic (12.0%). And the three commonest cross-family routes all end at floral: fruity→floral 9,689, herbal→floral 7,809, green→floral 7,707. Follow this list and it pulls you toward floral.
Beginner perfumer · 81 2025-09-17 9 min read Every material has two blending lists, and they point in different directions The database's blending suggestions split into odour and flavour. 7,035 materials have both, and the two overlap only partly — the median intersection over union is 0.379, and over the shorter list it is 0.600. What is interesting is the direction: 24.3% of the odour half points at floral, while in the flavour half floral is only third at 10.9%, with fruity at 12.1% and citrus at 11.1% ahead of it. One database, one set of materials, two lists with different centres of gravity. So "what does this material go with" first requires knowing whether you are making a perfume or a flavour.
Beginner perfumer · 82 2025-09-21 11 min read 156 records carry human toxicity data, and 57 of them involve children Toxicity fields mostly talk about rats and mice. But 156 records in this database carry a human figure — labelled oral-man (102), oral-child (57), oral-human (67) and oral-woman (1). Of those, 121 report a TDLo (lowest published toxic dose) and 89 a LDLo (lowest published lethal dose). And the best-supplied entries are not obscure chemicals: tea tree oil at 101 suppliers, methyl salicylate at 88, acetic acid at 82, coumarin at 74, camphor at 66, bitter almond oil at 37. All of these are ingestion figures and have nothing to do with the dose you put on skin — but their existence says one thing plainly: these materials have been through an emergency room.
Beginner perfumer · 83 2025-09-25 11 min read 94.5% of the dermal toxicity field is a rabbit's lethal dose, and sensitisation appears once Last time I counted the records carrying human data. This article steps back to a more basic question: does the toxicity field measure the route you actually use? Of the 3,156 materials with ten or more suppliers, 51.7% have oral toxicity data, 31.2% dermal, and just 6.6% inhalation — the route a perfumer never uses has the best coverage. And opening those 985 dermal entries does not give you what you need: 94.5% are LD50 lethal doses, 888 of them in rabbits, while "sensitisation" appears in one record and "irritation" in four. The field that answers dermal questions is ghs_classification, not toxicity_dermal.
Beginner perfumer · 84 2025-09-29 11 min read One field looks like a versatility ranking for materials, and seven of its top hundred have no suppliers at all The database has a field nobody uses called potential_uses, recording which accord types a material can go into — 7,807 records and 72,233 fragrance uses, from herbal, woody and floral to fougère, chypre and oriental. It looks like exactly what a beginner wants: an objective versatility ranking. Cross it against supplier counts and it breaks. Of the top hundred by accord breadth, 38 have fewer than ten suppliers and 7 have none; of the top five hundred, 33 have none. Its Spearman correlation with supplier count is only 0.365. The sharpest counterexample is patchouli oil: measured across 954 formulas it spans all fourteen types, while this field gives it 77 accords — behind a zdravetz absolute with zero suppliers.
Beginner perfumer · 85 2025-10-03 12 min read Rescuing the field that failed last time: add one specificity condition and it becomes a usable accord palette Last time I showed that potential_uses does not work as a versatility ranking — seven of its top hundred have no suppliers. But the field is not junk; I was reading it the wrong way round. Run it backwards: the chypre tag covers 506 materials and fern 752, with 57% of each having ten or more suppliers. The second condition is specificity — linalool is tagged with 269 accords, so its chypre tag carries no information, while cistus twig/leaf absolute is tagged with seven, one of which is chypre, and that tag carries a lot. Filtered that way the lists read like real palettes: cistus absolute, isobutyl quinoline and geranium absolute for chypre; lavandin absolute, hyssop oil and birch tar oil for fougère.
Beginner perfumer · 86 2025-10-07 14 min read I looked up every material name in 954 formulas. 53.7% missed — and that is not a coverage problem I took 954 deduplicated public formulas, pulled out the 2,994 distinct material names inside them, and looked up every one. The name field matched 1,186 (39.6%); the synonym field caught another 199 (6.6%); 1,609 missed — 53.7%. But sort the misses by how often they occur and the top twenty are almost all things a person recognises instantly. The most frequent is dipg at 445 occurrences: an abbreviation for dipropylene glycol. Then hedione, iso e super, cinnamic alcohol, linalol, styrallyl acetate. All of them are in the database under a different string. I sorted the gap into six kinds. Each has a different fix.
Beginner perfumer · 87 2026-01-03 15 min read The shelf life field is on 3.1% of records, and it holds only four numbers Of 42,225 materials, 1,303 state a shelf life — 3.1%. And 96% of those land on four round numbers: 24 months on 561 records, 12 on 397, 6 on 186, 36 on 111. Every entry ends with the same clause: 'or longer if stored properly.' That is a floor, not an expiry date. And the number does not track oxidation risk — sweet orange peel oil gets 36 months while its terpene-stripped folded version gets 12, which is backwards. The information you can actually act on sits in a different field, and that field has only four possible strings. One of them is 'refrigerate.'
Beginner perfumer · 88 2026-01-20 13 min read 348 records give the dose in millilitres, and a millilitre is not a dose 5,108 records carry a toxicity figure in mg/kg. 348 carry one in ml/kg. Turning a volume into a dose requires a density, and only 126 of those 348 (36.2%) have a specific gravity on file — the other 222 cannot be converted from the database alone. Worse, 16 of them give ml/kg for something the appearance field calls a powder, crystals, or a waxy paste, where millilitres correspond to no meaningful amount fed to anything. But the field carries its own antidote: 85.1% of the ml/kg records also hold an mg/kg number in the same cell, so the two can be checked against each other. Acetophenone's cell holds 3000 mg/kg, 3200 ml/kg and 2.48 ml/kg at once — and converting shows that the 3200 is the right number with the wrong unit.
Beginner perfumer · 89 2026-02-05 11 min read Of the 145 records told to refrigerate, 13.8% are carboxylic acids. Among the other records with storage conditions, it is 1.5% Last time I found that the storage field holds only four strings across the whole database, and that its strongest instruction — refrigerate — lands on 145 records. This time I went to see what those 145 are. They are not the most volatile: the refrigerate group's median boiling point is 229°C against 214°C for the rest. The real difference is chemical class. Records whose name ends in 'acid' make up 13.8% of the refrigerate group and 1.5% of the others — 9.4 times over. Sulfur compounds run 4.8% against 1.3%. And the other half of the story is that these 145 records are barely fragrance materials at all: 35.2% have 'fragrance' in the category field, against 79.7% for the rest.
Beginner perfumer · 90 2026-02-21 15 min read I guessed wrong last time: the storage field is not derived from chemistry, it arrives with the record's source Last time I found carboxylic acids 9.4× enriched and sulfur compounds 3.8× in the refrigerate group, then tossed off a guess about the leftover ionones and damascone: conjugated ketones, photo-oxidation. This time I tested that guess. It failed — unsaturated aldehydes and conjugated ketones are only 1.6× enriched. What killed it outright was testing within the family: α-ionone and β-ionone say refrigerate, δ-damascone and α-damascone say cool dry place, dihydro-β-ionone says store under nitrogen. And the cleanest pair is (E)-β-damascone and β-damascone — same FEMA 3243, same formula, same boiling point and logP, one told to refrigerate and one not. Nobody derived this field from chemistry.
Beginner perfumer · 91 2026-03-09 12 min read 330 FEMA numbers cover more than one record, and 64.2% of those groups contain more than one CAS Last time I hit (E)-β-damascone and β-damascone sharing FEMA 3243 while every field disagreed. This time I turned that into a probe and swept the database: 3,617 records carry a FEMA number across 2,968 distinct numbers, and 330 of those numbers (11.1%) cover more than one record, involving 979 records in total. 64.2% of those groups hold more than one CAS; 61.5% hold more than one odour description. The most extreme is FEMA 2825, which covers 20 records — a dozen origins and processing variants of sweet orange peel oil, plus one 'sweet petitgrain oil,' which is a different plant part. And the group that matters most is FEMA 2665: l-menthol, dl-menthol, d-menthol, (±)-menthol. Four CAS numbers, four stereochemistries, one number.
Beginner perfumer · 92 2026-03-25 13 min read Vanilla extract has 109 suppliers, and its odour field holds one word: vanilla Ylang ylang grade I gets ten descriptors and 319 hours of substantivity data. Grades II and III, which have more suppliers between them, get two words: 'floral; ylang'. So I measured whether description depth tracks commercial importance. Overall it does — across the 6,913 records with an odour field, the median runs from 3 descriptors at zero suppliers to 8 at fifty-plus, Spearman ρ = 0.433. But 56 records break the line: twenty or more suppliers and only one or two descriptors. And 55.4% of those 56 have a descriptor that is simply their own name — vanilla extract says vanilla, peppermint oil says peppermint, garlic oil says garlic. In the well-described control group it is 22.0%. This field cannot describe the things that are themselves the definition.
Beginner perfumer · 93 2026-04-14 12 min read The evaluation concentration field holds five values, and this time the ladder is real My last few articles have been about fields that do not mean what they say: shelf life is four round numbers that do not track oxidation risk, storage arrives with the record's source, a FEMA number is not an identifier. This one goes the other way. Of the 8,298 records with an evaluation entry, 7,620 (91.8%) state a concentration, and there are only 14 distinct values — five decade rungs (100%, 10%, 1%, 0.1%, 0.01%) cover 99.6%. It looked like another sorted-not-measured field. But crossed against strength rank, the correspondence is perfectly monotonic: at 100% the strongest rank is 0.3% of records, at 10% it is 28.3%, at 1% it is 82.4%, at 0.1% it is 86.5%, and at 0.01% it is 100%.
Beginner perfumer · 94 2026-04-30 15 min read Pull every 'A to B' where A exceeds B: 55 of them, and 23 hide a real error Last time I noticed two records giving an evaluation concentration of 1000%, and a concentration cannot exceed 100%. That suggested a whole class of checks that need no chemistry at all — the shape of a field is enough to expose an error. This article runs three: physical ceilings, plausible ranges, and the most useful one, range ordering. Across assay, specific gravity, refractive index, boiling point and melting point there are 42,802 'A to B' ranges, and in 55 of them A is larger than B. They split into two kinds: 32 are merely written backwards (ratio ≤1.15 — the values are fine but they break any parser), and in the other 23 the inversion exposes a real error, five of them with a ratio of exactly ten, which is a lost decimal place.
Beginner perfumer · 95 2026-05-12 14 min read I tried to compute the optimal starter kit from the official blending suggestions, and got 16 materials of a single odour type The database holds 673,662 blending suggestions. Taking the odour half, keeping only pairs where both sides have ten or more suppliers, leaves 51,138 undirected links among 2,271 materials. I wanted to ask a constructive question: which materials should you buy so that the set produces the most officially recommended pairings among themselves? A greedy search found a first complete cluster of 9, five of them balsamic. And four thousand randomised greedy runs found a largest clique of 16 — every one of them caramellic. Maltol, ethyl maltol, strawberry furanone, cyclotene: sixteen materials all recommending each other, and sixteen ways of writing the same thing. Overall, same-type links are only 17.7% (5.8% expected by chance, a 3.1× enrichment), so the field is not an echo chamber — but its densest regions are.
Beginner perfumer · 96 2026-05-28 13 min read I was comparing hours that cannot be compared — and half the '400 hours' in my own map were measured diluted The substantivity field reads 'N hours at M%', and I had only ever read the first half. Of the 2,027 records with a substantivity figure, 165 (8.1%) were not measured neat: 83 at 20%, 58 at 10%, and a handful at 1%, 0.1% and 0.05%. There are two distinct reasons and the data separates them — the 20% tier is 84.3% solids and resins (you cannot put a crystal on a blotter) but only 13.3% at the highest strength rank, while the 10% and 1% tiers run above 60% at rank 3. And 334 records read exactly 400 hours, of which 80 were measured at a dilution. Going back to my own palette map: of the 18 rows quoting a specific 400-hour figure, 9 came from diluted measurements. I have corrected all three language versions.
Beginner perfumer · 97 2026-06-13 15 min read Only 5.1% of records carry a Cramer class, and Class III does not mean toxic The database has a field called structure_class whose only values are I, II and III, and just 2,174 of 42,225 records have one — 5.1%. It is the Cramer decision tree classification, the first step of the threshold of toxicological concern procedure. There is a reason coverage is so low: records with a class have a FEMA number 68.0% of the time and a JECFA listing 63.8% of the time, against 5.3% and 2.2% for records without one. The field arrived with food flavouring safety assessments. The distribution runs Class I 60.3%, Class II 24.1%, Class III 15.4%, and the share of sulfur-named materials climbs monotonically from 12.8% in Class I to 32.2% in Class III. But Class III does not mean toxic — it means the structure offers no basis for presuming safety, which is to say the tree could not place it in a low-concern box and the conversation has to move to intake.
Beginner perfumer · 98 2026-07-04 14 min read Fragrance splits the flower, flavour splits the fruit — one apple tree, two vocabularies The potential uses field's tags come in two halves, FR for fragrance and FL for flavour, and their shapes are nothing alike. FR has 522 tag kinds across 72,233 occurrences, averaging 138 each. FL has 590 kinds but only 11,132 occurrences, averaging 19, with a median of 3. Only 119 tags appear on both sides — 403 are FR-only and 471 FL-only. The difference is not just volume: the top FR-only tags are woody, balsam, amber, fern, oriental, chypre, which is the entire classical perfumery vocabulary, while the top FL-only tags are tropical, tea, nut, chocolate, meat, tomato, cheese. The cleanest comparison is the apple: FL carries 25 apple tags and distinguishes Fuji, Gala, Golden Delicious, Granny Smith, McIntosh and Red Delicious; FR carries six, one of which is apple blossom at 237 uses — while flower tags on the FL side occur nine times in total.
Beginner perfumer · 99 2026-07-16 12 min read What crosses over is edible: dual-use materials have a supplier median of 11, fragrance-only materials 4 Last time I measured the two vocabularies in the uses field. This time I look at the materials themselves. Of the 7,807 records carrying the field, 34.5% have fragrance tags only, 15.2% flavour tags only, and 24.3% have both. The dual-use group is plainly better supplied — a supplier median of 11 against 4 for fragrance-only and 6 for flavour-only, and 11.2% of them have fifty or more suppliers against 2.6% and 1.6%. More interesting is which odour types cross over: caramellic 61.7%, waxy 56.9%, fatty 54.7%, green 53.1%, vanilla 51.2%, nutty 51.1% — all things you can eat. And at the bottom: amber at 11.6%, woody 22.5%, sulfurous 24.3%, floral 25.4%. Amber is not a food and not a plant. It is a concept perfumery invented.
Beginner perfumer · 100 2026-08-05 14 min read Article 100: four fields look 100% filled and are actually 12.3%, 6.2%, 1.7% and 20.9% This is the hundredth article in the beginner series, and what it should leave behind is not a reflection but a table. I counted coverage for thirty fields across all 42,225 records — the fullest is CAS at 73.5%, the emptiest is GHS hazard statements at 0.9%. But the ones to watch are the four that look 100%: notes and the three toxicity fields. Every record has text in them, and that text is 'None found' and 'Not determined'. Strip the placeholders and notes is 20.9%, oral toxicity 12.3%, dermal 6.2%, inhalation 1.7%. A field that is 100% full and 88% empty. If this hundred articles leaves one thing, it is this: ask first how many records actually have something in that field.
Beginner perfumer · 101 2026-08-17 11 min read One more correction to last time's table: the assay field's coverage is not 64.5%, it is 10.5% Article 100 listed coverage for thirty fields and caught four that look 100% full and are under 12% real. Running the same sweep across every field turned up an error in my own table. I reported assay at 64.5%, but 22,771 of those 27,221 records carry the identical string '95.00 to 100.00' — 83.7% of them. Strip it and what remains is 4,450 records, 10.5%. And that default tracks obscurity almost perfectly: among records with zero suppliers 97.5% of assay values are the default, against 26.5% among those with ten or more. There is also a more complete kind of empty: the chembl field has 5,831 values, and all 5,831 of them are the word 'View' — a button on a web page, not data.
Beginner perfumer · 102 2026-09-02 12 min read 794 records give a flash point of 0 °C, and every one of them is something that cannot burn The flash point field has 33.9% coverage, and its most common value appears 794 times: '32.00 °F. TCC (0.00 °C.) (est)'. A third of those 794 have no carbon in the formula — sodium hydroxide, sulfuric acid, titanium dioxide, calcium carbonate, chitosan. They have no flash point because they do not burn. And 0 °C is the most hazardous reading a regulation recognises: it means this ignites at freezing. The default says the opposite of the truth. Worse, not one of those 794 records carries a GHS hazard statement — the only field that could correct it is empty exactly where the lie is. And 56.6% of all flash point values are marked (est), which turns out to be almost entirely a property of materials nobody sells: est records have a supplier median of 1, non-est records 5.
Beginner perfumer · 103 2026-09-10 12 min read Each order of magnitude of vapour pressure costs about a factor of three in substantivity — top, heart and base are computable from a spec sheet The last several articles have taken fields apart. This one does the opposite: it computes something usable out of vapour pressure. Taking the 1,288 records that have both a vapour pressure and a substantivity measured at 100%, the Spearman correlation is −0.647, and banding them is perfectly monotonic: below 0.0001 mmHg the median substantivity is 336 hours, 0.001–0.01 gives 142, 0.01–0.1 gives 48, 0.1–1 gives 12, and 1–10 gives 4. Roughly threefold per decade. Cut at 1 and 0.01 mmHg and the three bands line up with the traditional top, heart and base — ethyl acetate and cis-3-hexenol on top, geraniol and linalool and linalyl acetate in the heart, the lactones and methyl dihydrojasmonate and methyl cedryl ketone at the base. With one large caveat: 94.0% of vapour pressures are estimates.
Beginner perfumer · 104 2025-03-24 13 min read 320 logP values fall outside the physically plausible range, and 319 of them are right I have been catching errors with range checks — purity cannot exceed 100, refractive index cannot fall below 1. Applying the same method to logP fails almost completely. 320 records fall outside −5 to +15, the extremes being inulin at −70.20 and sucrose hexastearate at 48.90, and both are correct: those are polysaccharides and lipids with molecular weights over a thousand, where extreme logP is real. There is exactly one genuine error — strychnine's logP reads 389.00 against a molecular weight of 334. Every other extreme comes with a molecular weight above 1,200. But those 320 records turned out to be useful for something else: only 0.9% of them have an odour type, against 19.2% for records inside the range. An out-of-range logP is not an error flag. It is a 'this is not an aroma material' flag, and it is 21 times more accurate at that.
Beginner perfumer · 105 2025-04-01 12 min read 14 records' molecular weight field holds the mass of the carbon atoms only, and I found it because the errors repeated Last time I caught one error by reading logP against molecular weight. This article finishes that method: compute the molecular weight from the formula and compare it with the field. Across the 20,626 records where both exist and the formula parses, only 22 disagree by more than 1% — 99.89% agreement, the cleanest field pair I have measured. And those 22 have a pattern: 180.16 appears three times, 228.21 twice, 252.23 twice, 276.25 twice, on molecules with completely different formulas. What they share is a carbon count. All three 180.16 records are C15; both 228.21 records are C19. And C15 × 12.011 = 180.165, C19 × 12.011 = 228.209. In these 14 records the molecular weight field holds the total mass of the carbon atoms in the formula. The hydrogens and oxygens were dropped.
Beginner perfumer · 106 2025-04-09 13 min read The median of 954 public formulas is 17 materials, and the largest component is a quarter of the whole 'Commercial perfumes contain hundreds of ingredients' is a thing people say. I have 954 deduplicated public demonstration formulas, and their median size is 17 materials, with nearly half (47.5%) falling between 10 and 19, only 11.0% above 30, and just four above 50. The distribution of component shares is equally clear: across all 17,481 components the median share is 2.50%, four in ten fall between 1% and 5%, and only 6.0% exceed 20%. The largest single component in a formula is a median of 25.0% of the total. The most practical number is the ratio: the largest component divided by the smallest has a median of 60 — which determines what scale you need, and why you make dilutions.
Beginner perfumer · 107 2025-04-17 19 min read Beginner perfumer #107: how much of each material do you actually use? An answer measured from 954 formulas For the 187 materials that appear at least 20 times across 954 public demonstration formulas, I computed each one's median share of the formula. The spread is narrower than I expected: the overall median is 2.11%, the highest is hexyl cinnamaldehyde at 16.16%, the lowest is Ambroxan at 0.20%, and the whole range is only 81-fold. The database's strength rank does predict that number (rho = -0.592), and the evaluation concentration predicts it better still (rho = 0.679). But one misreading needs killing first: the evaluation concentration falls 100-fold from 100% to 1%, while the real dose falls only from 3.88% to 0.75%, a factor of 5.2. The evaluation concentration is a ranking, not a dosing table.
Beginner perfumer · 108 2025-04-29 20 min read Beginner perfumer #108: when the boiling point and the melting point hold the same number 2,676 materials carry both a melting point and an atmospheric boiling point, and in 11 of them the two numbers are identical. Nothing boils at its melting point at atmospheric pressure, so in those 11 one field has been copied from the other. The clue that settles which is the appearance field: 7 are described as liquids at room temperature, which rules out a melting point of 66 to 261 °C, so the melting point field is the broken one; 7-methyl coumarin is described as a powder, so its 128 °C is a real melting point and the boiling point field is the broken one. A second check confirms it. Of 1,258 materials carrying both an atmospheric and a reduced-pressure boiling point, only 2 show the physical impossibility of the reduced-pressure value being higher, and 7-methyl coumarin appears on both lists. Along the way my own regex ate acetaldehyde's minus sign and over-reported by one.
Beginner perfumer · 109 2025-05-07 18 min read Beginner perfumer #109: I guessed the substantivity field inflates at the long end, and I was wrong Two materials in a row carried substantivity values several times what their family's vapour pressure predicted, so I guessed the field over-reports systematically at the long end. This round I tested it. Removing all 137 materials listed at 400 hours moves the correlation between vapour pressure and substantivity from -0.659 to -0.644, which is nothing. The hypothesis does not hold. Two more useful things fell out along the way: 400 hours accounts for 16.5% of all substantivity values and 35.9% of everything at 100 hours or more, making it a bucket label rather than a measurement; and the vapour pressures behind every substantivity value span four to seven orders of magnitude, so the long end is not worse than the rest. What is clean is the bucket medians. A log-log fit across 12 buckets gives R² = 0.927 and a slope that works out to roughly 5.85x substantivity per decade of vapour pressure. The 'about 3x' I published in #103 was computed at the individual-material level and had been flattened by noise.
Beginner perfumer · 110 2025-05-15 16 min read Beginner perfumer #110: ninety-five thousand aliases that match three more names Three rounds in a row I hit the same wall: the names the corpus uses do not match the names in the database. This round I went to look at the database's alias field, which holds 25,980 materials and 95,214 aliases. Then I found that 87.9% of the entries are truncated fragments. Geraniol's alias is '(2E)-3,7-'. Vanillin's is '4-'. Linalool's is '3,7-'. Menthol's is 'L-'. The cut is not at a fixed character count; fragment lengths run to a median of 4, quartiles of 2 and 7, and a maximum of 84. It falls on the boundary between the nomenclature prefixes and the parent name, and 95.2% of fragments consist entirely of locants, stereodescriptors, and prefixes like iso and bis. The practical effect is plain: the name field matches 54.9% of the corpus's component records, adding head_synonym takes it to 60.3%, and adding all 95,214 aliases takes it to 60.4%. Three more names, fourteen more records.
Beginner perfumer · 111 2025-05-27 18 min read Beginner perfumer #111: one parenthesis worth two thousand rows — which name normalisation actually pays The last article closed by saying normalisation should push the number higher and that I had not tried. This is the result. I split name normalisation into four layers and measured how many formula records each one recovers. Stripping punctuation and whitespace and unifying stereodescriptors like cis and (Z) recovers 147 records between them. Stripping dilution markers like '50% in DPG' recovers 16. Stripping the manufacturer parenthetical off the database name — (IFF), (Firmenich), (Givaudan) — recovers 2,003, more than ten times everything before it combined. The database stores hedione (Firmenich) while perfumers write hedione, and that one name accounts for 165 formulas. Coverage moves from 60.32% to 72.81%. But you cannot strip parentheses blindly: of the 1,096 names ending in one, 26 read (mixture of isomers) and 22 read (salt), and stripping those merges materials that are not the same.
Beginner perfumer · 112 2025-06-04 19 min read Beginner perfumer #112: the aldehyde C-number stops being a carbon count at C-12 The 954-formula corpus holds 501 records written in the old aldehyde C-numbering, across 28 spellings. I resolved every one of them back to the database and built a lookup table. C-6 through C-12 are honest: the number is the carbon count and the material really is an aldehyde. From C-14 it stops. Aldehyde C-14 is gamma-undecalactone, eleven carbons, a lactone rather than an aldehyde. C-16 is ethyl methylphenylglycidate, twelve carbons, an epoxy ester. C-18 is gamma-nonalactone, nine carbons. And the database itself appends so-called to all three names. I also checked one thing before merging: across these eight pairs, no formula ever uses both spellings, so every overlap is zero and merging is safe. After merging, gamma-undecalactone moves from 29th to 15th in the corpus, and decanal from 44th to 25th.
Beginner perfumer · 113 2025-06-12 19 min read Beginner perfumer #113: the real materials leaderboard, once the names are merged Over four rounds I have accumulated three merge rules: strip the manufacturer parenthetical, look up the aldehyde C-numbers, and add twelve hand-written aliases. Coverage moves from an initial 54.9% to 81.98%. Those twelve hand-written lines recover 955 records; the database's own 95,214 aliases recover 14. Merging changes the leaderboard's shape. Looking up dipropylene glycol by the database's official name shows 32 formulas when the real figure is 470, a factor of 14.7. Styralyl acetate shows 26 against a real 135. Verdox, filed as green acetate, shows 16 against 75. More extreme still, some materials' official names never appear in the corpus at all: Iso E Super is filed here as patchouli ethanone, and searching that name returns nothing. The remaining 3,150 records split into two types, and 795 of them are a natural-material grading problem rather than a naming one.
Beginner perfumer · 114 2025-06-20 17 min read Beginner perfumer #114: the formula says 'ylang ylang oil', the database has 22 records, which do you buy? The naming problem stopped moving at 82% because what remains is not a spelling problem. The corpus holds 16 spellings of ylang across 152 formulas, 113 of which write the unqualified 'ylang ylang oil' and exactly 2 of which name a grade. The database holds 22 ylang records. The differences between the four main candidates are real: grade I lists a substantivity of 319 hours and ten words in its odour field; grades II and III list two words each, 'floral; ylang', and have no strength rank at all. The unqualified record reads 140 hours and five words, and its CAS number differs from all three grades. This is not a name mismatch; it is the corpus naming things at a coarser grain than the database. As for scale: 39 natural-material names appear 15 or more times in the corpus, each matching a median of 21 database records, and lemon oil matches 98.
Beginner perfumer · 115 2025-06-28 18 min read Beginner perfumer #115: the formula says lemon oil, and the most-supplied of its 98 candidates is lemongrass Last article I computed that the corpus's lemon oil matches 98 database records. This one opens them up. The record with the most suppliers is lemongrass oil at 88, which is a grass with no relation to the lemon tree; the two share four letters at the start of a string. Among the real candidates, the widest gap is this: lemon oil lists a substantivity of 4 hours and lemon oil folded lists 264, and both carry the identical CAS number 8008-56-8. A folded oil is what remains after more than 90% of the terpenes are removed, and that sentence comes from the database's own notes field. It leaves a verifiable trace in the optical rotation: the crude oil reads +57 to +65.5, and the deterpenated oil reads -8 to -10. The sign flips. Specific gravity separates them too, 0.849 to 0.855 against 0.885 to 0.897, with no overlap.
Beginner perfumer · 116 2025-07-06 19 min read Beginner perfumer #116: optical rotation, the one field you can verify yourself after buying Only 359 materials in the database (0.9%) carry an optical rotation, but the information density in those 359 is high. The deterpenation ladder is perfectly monotone across five citruses: lemon goes from +57~+65.5 to -8~-10 when deterpenated, sweet orange from +94~+99 to +78~+91 folded and +11~+24 terpeneless, lime from +34~+47 to -9~+2 folded and -9~-11 terpeneless, grapefruit from +91~+96 to +15~+22. The substantivity field confirms the same mechanism independently: sweet orange runs 140 hours whole and 212 deterpenated. Following that line turned up two errors. laevo-menthol has 114 suppliers and an optical rotation of -1 to +2, while every other laevo- or dextro- material in the database agrees with its own name, including menthol's own acetate ester at -70 to -75. And lime oil expressed reads +35.00 to -41.00 where its Mexican sibling reads +41.00 to +35.00; that minus sign is a typo.
Beginner perfumer · 117 2025-07-14 19 min read Beginner perfumer #117: when both ends of a spec are round numbers, the range is three to five times wider Refractive index and specific gravity are the two fields in this database that look most like measurements. Sweeping four thousand-odd materials, the median range width is 0.0060 for refractive index and 0.0080 for specific gravity. Then a signal turned up that needs no chemistry at all: when both endpoints are round to two decimal places, as in 1.40000 to 1.60000, the median width is 0.0200, which is 3.3 times the rest. For specific gravity it is 0.0300 against 0.0064, a factor of 4.7. Round endpoints mean the interval was typed rather than measured. Following that line, 38% to 54% of the wide ranges belong to records whose names contain fragrance or specialty: compounded blends, which cannot have a single specification in the first place. I also tested one hypothesis, that unpopular records go unchecked. It failed. The correlation between supplier count and spec width is only -0.055.
Beginner perfumer · 118 2025-11-16 18 min read Beginner perfumer #118: of 42,225 materials, about 4,850 are fragrance materials This database's front page says 42,225 materials. This round I cut it four times. First cut: 6,457 records whose category field itself reads 'information only not used for fragrances or flavors'. Second cut: 2,829 blends whose names contain fragrance, specialty, flavor or replacer, a group where only 3% carry a CAS number against 79% of everything else. The third cut is the largest: 27,277 records have an entirely empty odour field, 65% of the database, because it also holds cosmetic ingredients, food additives and pharmaceuticals. Fourth cut: 808 records with no suppliers at all. What remains is 4,854 records, 11.5%, that have suppliers, have an odour, and are not marked as non-fragrance. And that number explains several of my earlier misreadings in retrospect: a logP range sweep flagged 320 anomalies of which 319 were correct, and a vapour-pressure regression's largest outliers were acyclovir and hydrocortisone.
Beginner perfumer · 119 2026-01-08 15 min read Beginner perfumer #119: 6,457 records say don't use it, and 8 say why Last round I found 6,457 materials whose category field reads 'information only not used for fragrances or flavors'. This round I went looking for the ones that used to be fragrance materials. The bar is low: an odour field and at least one supplier. Only 87 qualify, 1.3% of that group. And of those 87, only 8 give a reason for withdrawal in a regulatory or notes field; 75 of them, 86%, say nothing at all. The best case is a pair of positional isomers. 6-methyl coumarin's notes field states outright that it is a synthetic fragrance causing contact photoallergy, and it has 35 suppliers, FEMA GRAS, and continued use. 7-methyl coumarin's notes field reads None found, yet it is marked as not used for fragrances and has 7 suppliers left. The one with a documented problem stayed; the one without documentation was removed.
Beginner perfumer · 120 2026-01-24 16 min read Beginner perfumer #120: the evaluation concentration really answers one yes-or-no question Two fields in this database carry a concentration: odor_strength's 'recommend smelling in an N% solution or less', and the 'at N %' inside odor_descriptions. Across the 797 materials that have both, 94.1% carry the same number. But their coverage differs sharply: the first exists on 802 records and the second on 7,620, and the first appears almost exclusively on materials that need diluting. This round I recomputed evaluation concentration against real dose using 604 materials resolvable to the corpus. Materials evaluated at 100% have a median dose of 2.50%; at 10%, 1.00%; at 1%, 0.86%; at 0.1%, 0.85%. The correlation is rho = +0.438, and dropping the 100% group takes it to +0.114. Nearly all the predictive power comes from one distinction, neat versus diluted, and the ladder below that is flat. This also corrects the rho = 0.679 I published in #107, which came from 117 materials; recomputed on 604 it is 0.438.
Beginner perfumer · 121 2026-02-09 15 min read Beginner perfumer #121: the 208 materials with two boiling points at one pressure A material can only have one boiling point at a given pressure. 208 records carry two or more, with a median gap of 5 °C and quartiles at 2 and 18. But the check comes with its own answer: in 187 of them (90%) one value carries est and the other does not, which is an estimate sitting beside a measurement, so you keep the unmarked one. The awkward cases are the 20 where neither is marked, and only 6 of those differ by more than 20 °C. The other 14 differ by 0 to 5 degrees and are simply duplicate entries, four of them with identical values. The two largest of the six are well supplied: 1,8-cineole (77 suppliers) reads 176–177 and 90–91, and dimethyl sulfide (81 suppliers) reads 37.30 and −37.50 to −37.30, the same digits with a minus sign, the third sign error I have found in this database.
Beginner perfumer · 122 2026-02-25 17 min read Beginner perfumer #122: values marked (est) agree with each other better, and that is exactly why their agreement proves nothing This database marks many numbers with est. The rates vary widely: xlogp3 is 100%, logP 99.7%, appearance 99.8%, vapour pressure 94%, boiling point 57.7%, and melting point only 4.2%. I used the boiling-point-to-vapour-pressure regression to test whether est values are less accurate. The answer runs against intuition. Restricted to fragrance materials with an odour field, the 518 records where both fields are estimates have a residual standard deviation of 18.7 °C with 1.0% exceeding 50 degrees, while the 186 where both are measured have 27.1 °C and 7.5%. The estimates are more consistent on every measure. The reason is not hard: two estimates come from one model and their agreement is by construction, while two measurements come from different laboratories and decades, where disagreement is normal. And that is the point. Consistency is not accuracy, so two estimates agreeing cannot be evidence that either is right. This also constrains a lot of the cross-field checking I have done myself.
Beginner perfumer · 123 2026-03-13 16 min read DPG vs IPM: two odorless solvents that share a catalogue entry, with all four numbers at opposite extremes In the database DPG and IPM look like the same material: both odorless, both logged at 400 hours of longevity, both cheap, both used for dilution. Put the fields side by side and all four numbers stand at opposite poles. LogP is −0.60 versus +7.20, nearly eight orders of magnitude apart; vapour pressure differs 97-fold; one is heavier than water, the other 20% lighter; one is fully miscible with water, the other barely dissolves. Meanwhile the 1,465 materials in this database that carry an odor profile have a median logP of +3.0 — neither solvent lives where fragrance materials live, they just stand on opposite outer edges. Dermatology literature gives IPM a second official identity: penetration enhancer. In 2017 neutron diffraction showed how it loosens the packing of stratum corneum lipids. Choosing a solvent is not choosing a background; it's choosing where your materials go and how fast.
Material guide · 1 2023-03-14 14 min read Material guide: linalool — the ubiquitous molecule that makes oxidation visible CAS 78-70-6, a monoterpene alcohol occurring in many aromatic plants. It is simultaneously the industrial feedstock for geraniol, nerol and citral, and a lead compound in vitamin A and E synthesis. Pure linalool does not sensitise; oxidised linalool does. Literature, our database record, and buying practice on one page.
Material guide · 2 2023-03-18 12 min read Material guide: bergamot — how one oil bridges a cologne from top to heart Bergamot combines citrus, floral, green and spicy facets, letting a cologne move from a bright opening into its floral heart. The catalogue includes whole, bergapten-reduced, terpeneless and reconstructed grades.
Material guide · 3 2023-03-22 14 min read Material guide: vanillin — the most-smelled fragrance molecule on Earth Vanilla ice cream, perfume bases, cola — all vanillin. In the vanilla pod it is made from ferulic acid by a single enzyme, VpVAN (only confirmed in 2014), and vanilla prices went through five bubbles between 1971 and 2020. Most of the world's vanillin is synthetic — this guide puts those two facts side by side. 193 suppliers; a starter-palette essential.
Material guide · 4 2023-03-26 15 min read Material guide: patchouli — the distance from musty earth to a clean woody base is one dilution 148 suppliers, top-of-scale substantivity, a 36-month shelf life — patchouli is one of the most durable natural base materials. Under the single name live two chemotypes (PA-type and PO-type), and the molecule perfumery wants, patchoulol, is important enough that yeast has been engineered to make it. The most acquired taste among the starter ten.
Material guide · 5 2023-03-30 13 min read Material guide: methyl dihydrojasmonate (Hedione) — why the catalogue search comes up empty Articles call it Hedione; supplier catalogues list methyl dihydrojasmonate — one material, one trade name, one chemical name. It is the transparent backbone of modern jasmine, stocked by 102 suppliers. With a magnifying-glass section on the science: it was identified as a ligand of the putative human pheromone receptor VN1R1, but that field is far from settled.
Material guide · 6 2023-04-04 13 min read Material guide: geraniol — an affordable rose structure from 198 suppliers Measured rose oils contain about 15.63–27.76% geraniol. It is one of rose odour's main structures and the widest-stocked material in the database, a practical start for a first rose accord.
Material guide · 7 2023-04-08 15 min read Material guide: citral — the actual lemon molecule, and IFRA's model student Lemon oil is mostly limonene; the molecule that actually says "lemon" is citral — the collective name for the twin aldehydes geranial and neral. It is also the worked example in the IFRA quantitative risk assessment paper, and the source of a 2.9% positive rate among 1,476 tested dermatitis patients. 135 suppliers: cheap, vivid, and a lesson in the price of brightness.
Material guide · 8 2023-04-12 12 min read Material guide: citronellol — the waxy rose structure often richer than geraniol Measured rose oils contain roughly 20.35–44.75% citronellol, overall more than geraniol. It supplies waxy thickness and soft sweetness, the second part of the rose trio.
Material guide · 9 2023-04-16 14 min read Material guide: phenethyl alcohol (PEA) — why rose water still smells of rose Phenethyl alcohol is among the most abundant compounds above fresh rose blossom. Because it dissolves readily in water, distillation sends it into rose water rather than keeping it in the oil. The last piece of the rose trio, with 110 suppliers.
Material guide · 10 2023-04-20 14 min read Material guide: sandalwood — the wood whose oil output fell to roughly a third Indian sandalwood consumption runs around 4,000 tonnes a year, while oil production fell from 180–200 tonnes across six decades to roughly 70 tonnes in the 2004 records. That is why the catalogue carries a whole row of replacers and Australian species. 81 suppliers; substantivity at the top of the scale.
Material guide · 11 2023-04-24 13 min read Material guide: cedarwood — the truth about the pencil smell: it is not actually cedar The Virginia and Texas cedarwoods of the catalogue are, botanically, junipers — the EFSA assessment states in black and white that Texas cedarwood comes from Juniperus deppeana. The scent core is cedrol: one 26-subject study found inhaling it lowered heart rate and blood pressure with a rise in parasympathetic activity. 85 suppliers, 388 hours of measured-looking substantivity — the wood family's cheapest workhorse.
Material guide · 12 2023-04-28 14 min read Material guide: menthol — cool is not a smell; it is your temperature receptor being tricked In 2002 two labs independently described a cold- and menthol-sensitive receptor (CMR1/TRPM8, later understood to be one channel) — so "cool" is somatosensation, not smell, and the two labs' heads went on to share the 2021 Nobel Prize. In the catalogue, laevo-menthol has 114 suppliers and dextro only 9: the market tells you which form nature makes.
Material guide · 13 2023-05-02 10 min read Material guide: ethylene brassylate — the most accessible macrocyclic musk CAS 105-95-3, soft, powdery, clean and faintly vanilla-sweet. With 52 suppliers and 208-hour substantivity, it is an inexpensive, quiet introduction to macrocyclic musks.
Material guide · 14 2023-05-06 16 min read Material guide: benzyl acetate — the flesh of the jasmine, and the shortest-lived material in this series It keeps appearing on the main-constituent lists of jasmine absolutes — sweet, fruity, the bite of a white petal. At 4 hours of substantivity it is the shortest-lived material in this series so far: not a flaw but the definition of a top note. And its family (benzyl acetate 4 h, benzyl alcohol 35 h, benzyl benzoate 322 h, benzyl salicylate 384 h) — one benzyl head, different acids — forms an evaporation curve all by itself. 100 suppliers.
Material guide · 15 2023-05-10 11 min read Material guide: beta-ionone — one molecule bridging violet and berries CAS 14901-07-6 combines violet, woody and berry facets. With 78 suppliers and 76-hour substantivity, this guide concentrates on how it moves from floral to fruit in a formula.
Material guide · 16 2023-05-14 12 min read Material guide: coumarin — the hay sweetness in tonka and the start of fougere CAS 91-64-5, the sweet core of tonka beans and a standard material in fougere perfumery. A white crystal with 364-hour substantivity and 74 suppliers; smell, family and buying stay in one guide.
Material guide · 17 2023-05-18 14 min read Material guide: cis-3-hexenol — the green of the very second the grass is cut, which is really a plant alarm CAS 928-96-1, the lead molecule of the cut-grass smell. Plants only produce these compounds in quantity once their tissue is damaged or stressed, and plant ecology studies them as signals between plants. Sensitivity to it has a genetic component, but the OR2J3 receptor haplotype explains just 26.4%, at the opposite end of the spectrum from beta-ionone's clean 96% case. High strength, 4-hour substantivity, 120 suppliers.
Material guide · 18 2023-05-22 16 min read Material guide: cinnamaldehyde — cinnamon's heat sits on the same family of switches as menthol's cold CAS 104-55-2, the body of the cinnamon smell. The menthol guide covered TRPM8, the cold switch; cinnamaldehyde presses another one in the same family, TRPA1, and the 2004 study found it the most selective at activating that channel among the compounds it tested. It is also one of the fragrance allergens the EU requires on labels, and a 1996 threshold study measured the concentrations and delayed reactions in already-sensitised subjects. 105 suppliers, 212-hour substantivity; this is where heat in perfume comes from.
Material guide · 19 2023-05-26 17 min read Material guide: gamma-decalactone — the creamy skin of a peach, and a handover of ripening smells CAS 706-14-9, the core lactone of peach. A 2010 study measured the handover as fruit ripens: green leaf volatiles step off, lactones step on, and gamma-decalactone is the principal volatile of the late ripening stage. Material labelled natural mostly comes from yeast fermenting castor-oil ricinoleic acid, and a 1998 study found the yeast also eats its own product. 111 suppliers, 256-hour substantivity; a rare base-note citizen of the fruity family.
Material guide · 20 2023-05-30 13 min read Material guide: isoamyl acetate — banana, banana oil, and the cheapest lesson in ester chemistry CAS 123-92-2, the body of the banana smell; the paint solvent Taiwanese hardware stores call banana water is named after it. A 1962 Nature paper identified it as an active component of the honeybee sting pheromone, and a 2003 brewing-yeast study proved the banana note in wheat beer comes from the yeast's ester synthases. High strength, evaluate at 1% or less, under 4 hours on the strip, flash point 25 °C. 93 suppliers; the first ester of the fruity starter kit.
Material guide · 21 2023-06-03 15 min read Material guide: beta-damascenone — the trace heavyweight in rose, and the myth of the lowest threshold CAS 23696-85-7, the star of the rose ketone family. The literature credits it with one of the lowest orthonasal and retronasal detection thresholds of any odorant, and honestly admits its sensory contribution to most products remains unclear; a 2021 Pinot Noir experiment showed the effect depends heavily on the matrix. A carotenoid-cleavage cousin of beta-ionone. 96 suppliers, 216-hour substantivity; a material you dose in ppm.
Material guide · 22 2023-06-07 15 min read Material guide: decanal (aldehyde C-10) — the waxy shine an orange peel sprays at you, and the aldehyde of "aldehydic" CAS 112-31-2, present in the peel oil that hits your face when you peel an orange. The aldehyde in the aldehydic family means this row of straight-chain fatty aldehydes, and C-10 is its citrus-peel specialist: a 2001 orange juice study ranked it among the dominant aroma contributors by odour activity value. A 1998 Science landmark also showed a single receptor responding to only a small subset of odorants. High strength, evaluate at 1% or less, and a 12-month shelf life that is unusually short for this series. 92 suppliers.
Material guide · 23 2023-06-11 18 min read Material guide: eugenol — the smell of the dentist's office, and the third switch of temperature perception CAS 97-53-0, the body of clove and the backbone of carnation accords. A 2006 study showed it strongly activates and sensitizes the warmth channel TRPV3, completing this series' temperature trilogy with menthol's TRPM8 and cinnamaldehyde's TRPA1 — and the same paper states plainly that these molecules are also skin sensitizers. The family's isoeugenol is the allergen under closer watch: five years of data on 3636 patients showed its contact dermatitis frequency rising, not falling. 97 suppliers, 52-hour substantivity.
Material guide · 24 2023-06-15 15 min read Material guide: maltol — the sweet air of cotton candy, and the two layers of the "sweetness enhancer" legend CAS 118-71-8, the body of the cotton-candy and caramel smell, and a standard material in the gourmand family. That odors can enhance perceived sweetness has growing empirical support; yet in the classic experiment, maltol ranked lowest of six sweet odorants, and at subthreshold concentration in the model sucrose solution showed no significant effect. 107 suppliers, 372-hour substantivity (measured at 20% in benzyl alcohol), a crystalline material evaluated at 5% or less.
Material guide · 25 2023-06-19 89 min read The starter palette, mapped: 180 materials on one page The material guide series now covers 180 materials. This is the map: a one-line role for each material, longevity in three tiers, evaluation strengths, and the storylines scattered through the series. All figures are compiled from our database records and the series articles.
Material guide · 26 2023-06-23 12 min read Material guide: linalyl acetate — the clean sweetness shared by lavender and bergamot CAS 115-95-7, the ester of linalool and acetic acid and the clean, sweet core shared by lavender and bergamot. 117 suppliers, with 20-hour substantivity.
Material guide · 27 2023-06-27 16 min read Material guide: galbanum — the king of green, and the best demonstration that main components are not the main smell CAS 8023-91-4, the resin oil of Persian Ferula species and the backbone of perfumery's green family. A 2009 study says it outright: monoterpenes make up the bulk of the oil yet hardly contribute to its distinct aroma, while trace pyrazines contribute significantly. One of them, the bell-pepper pyrazine, marks red wine with a clear green-pepper character at 15 nanograms per litre. 66 suppliers, high strength with a 1%-or-less evaluation advice, 72-hour substantivity.
Material guide · 28 2023-07-01 17 min read Material guide: heliotropin — the flower in its name doesn't contain it, and neither does the vanilla legend CAS 120-57-0, a cherry-almond-powdery sweetness named after the heliotrope flower. A 2007 study went looking for it in the flower and found none; the bloom's scent is mainly anisaldehyde and benzaldehyde. The legend pinning it to Tahitian vanilla was also settled by quantitation: under one part per million in authentic beans. 74 suppliers, 212-hour substantivity, and the third lesson in names parting ways with facts.
Material guide · 29 2023-07-05 16 min read Material guide: rose oxide — the rose you smell when peeling a lychee, and a class reunion in one paper CAS 16409-43-1, the lead of the green, metallic rose scent inside lychee shells. A 1999 study compared lychee with Gewurztraminer wine and found 12 shared odor-active compounds, with cis-rose oxide holding the highest odor activity value among the shared odorants of all three; half the list are alumni of this series. A 2008 study adds stereochemistry: fermentation shifts its enantiomeric ratio. 77 suppliers, high strength with a 1%-or-less evaluation advice, a top note lasting past 8 hours.
Material guide · 30 2023-07-09 15 min read Material guide: alpha-irone — the scent that waits years inside a root CAS 79-69-6, the lead of orris root's violet-powder scent. The scent is not there at harvest: irones form slowly during storage by oxidative degradation of triterpenoid iridals, and research has monitored rhizomes stored from six months to nine years. Analysis of Ukrainian orris oil found fatty acids dominating and alpha-irone at just 2.85%, yet irone content is the accepted criterion of commercial quality. 29 suppliers, 104-hour substantivity.
Material guide · 31 2023-07-13 15 min read Material guide: ambroxan — ambergris that no longer needs the whale CAS 6790-58-5, the true face of "ambergris" in modern perfume. A 2023 review calls it the most prominent olfactive component of ambergris: industry long made it by semisynthesis from clary sage's sclareol, and now a 100% renewable route runs from fermented beta-farnesene through an engineered enzyme cyclisation. Three generations of production, with the whale stepping offstage. 61 suppliers, high strength with a 1%-or-less evaluation advice, a substantivity record past 400 hours.
Material guide · 32 2023-07-17 13 min read Material guide: galaxolide — the clean-laundry smell in detergent CAS 1222-05-5, a flagship polycyclic musk and a major source of clean-laundry odour in detergent and body wash. The neat material is viscous, substantivity reaches the top of the scale, and four 50% dilutions sit beside it.
Material guide · 33 2023-07-21 19 min read Material guide: oakmoss absolute — the chypre foundation, and the atranol story CAS 977059-15-6, the absolute of the lichen Evernia prunastri: a dark base of green, wood, earth, seaweed and hay, and the foundation of the chypre family. Research in 2003 identified the hidden allergen chloroatranol in it, and in 2017 the EU added atranol and chloroatranol to the prohibited list for cosmetics. The ban targets two molecules, and oakmoss with the allergens removed stays on the market: catalogs carry 42 suppliers of the real thing and 21 of replacers, and the low atranol and IFRA wording in product names is this history written out.
Material guide · 34 2023-07-25 17 min read Material guide: vetiver — a riddle hidden in a grass root, solved in 2021 CAS 8016-96-4, an essential oil distilled from the roots of a grass; the paper's abstract claims it appears in over a third of all fragrances. A mixture of hundreds of molecules whose signature odorant stayed unresolved for a long time: in 2021 the List and Kraft team proved by an eleven-step synthesis that the smelling principle is (+)-2-epi-ziza-6(13)-en-3-one, with a threshold of 29 picograms per liter of air. 43 suppliers, 400 hours measured neat, a catalog family with origins written into product names, plus two derivatives: vetiveryl acetate and vetiverol.
Material guide · 35 2023-07-29 17 min read Material guide: Iso E Super — the invisible wood that can carry a whole perfume CAS 54464-57-2, a transparent woody-amber molecule: soft, dry, skin-like. Our database lists it as patchouli ethanone, though the trade name Iso E Super is far better known; 79 suppliers. One brand famously sold a long-running perfume made of little else than this molecule (trade lore). High-volume molecules also draw heavy scientific scrutiny: RIFM's aquatic risk assessment and a new-methodology study of its thyroid effects, two 2024 papers read together.
Material guide · 36 2023-08-02 15 min read Material guide: tonka bean — coumarin's hometown, sweet like caramel and hay CAS 8046-22-8, the absolute of the Dipteryx odorata bean: sweet, warm, coumarinic, nutty, caramellic. The very word coumarin comes from the bean's Tupi name kumarú (lore). 40 suppliers, a dark brown solid, 400 hours of longevity, and a database field that outright recommends evaluation at 10% or less. Two 2022 papers: the first comparison of plant parts across the Dipteryx genus with its Amazon gatherer economy, plus a food study finding roasting beats boiling.
Material guide · 37 2023-08-06 17 min read Material guide: labdanum — the chypre triangle's last corner, amber's botanical home CAS 8016-26-0, the resin and absolute of the rockrose Cistus ladanifer: amber, ambergris, old wood, sweetness and a touch of mustiness. The chypre triangle from the oakmoss guide (bergamot, labdanum, oakmoss) is completed here. 58 suppliers, a dark brown solid, 400 hours of longevity (measured at 20% dilution). A 2024 study compared the traditional Zamorean and Andalusian harvesting processes (the latter yields 25-fold more), and a 2025 review mapped the whole plant's value from essential oil to by-products.
Material guide · 38 2023-08-10 16 min read Material guide: frankincense — a resin burned for millennia, its churchlike endnote pinned down in 2016 CAS 8016-36-2, the essential oil distilled from Boswellia resin: terpenic, incense, pepper, pine and green. The literature calls it one of the oldest aromatic materials used by humans, yet the molecular source of its signature smell was only found in 2016 — the olibanic acids, present at ppm levels, carrying the old-churchlike endnote. It has broad supply from 93 suppliers; the sister species Indian frankincense and climate-driven habitat contraction are its modern problems.
Material guide · 39 2023-08-14 15 min read Material guide: myrrh — the resin trilogy's close, a bittersweet balsam CAS 8016-37-3, the essential oil distilled from the oleo-gum resin of Commiphora myrrha: balsamic, dry, spicy, amber, toffee — plus mushroom and metallic, two rare odor terms. Etymology lore traces the name to a Semitic root meaning bitter. Pharmacology gave it two footnotes: a 1996 Nature letter titled on its analgesic effects, and a 2000 study of sesquiterpenes with local anaesthetic activity that block sodium currents. 64 suppliers, 400 hours of longevity, and the resin trilogy (labdanum, frankincense, myrrh) completes here.
Material guide · 40 2023-08-18 18 min read Material guide: jasmine absolute — one flower, two faces: grandiflorum and sambac The white-floral family's original finally takes the stage. The catalog spells out both species: Jasminum grandiflorum (the perfume tradition) and J. sambac (the tea world), the latter leading with 56 suppliers. The words from chassis in product names are a fossil from the enfleurage era (lore). Two 2026 studies: a four-species volatile comparison aimed at authentication (157 components), and sambac's monthly dynamics — total detected volatiles peak in August, and decanal's name appears among 17 potential key differentiating volatiles.
Material guide · 41 2023-08-22 18 min read Material guide: rose absolute — the rose line's finale, the flower itself arrives last This series covered the rose trio of geraniol, citronellol and phenethyl alcohol, then the finishing touches of beta-damascenone and rose oxide; the flower itself closes the line. CAS 8007-01-0, the absolute of the damask rose: floral, waxy, spicy, green — with metallic showing up again in the DB odor terms. 47 suppliers, 168 hours of longevity. Two processes (distilled otto versus solvent absolute), two species (damascena and centifolia) and three origins written into product names, the same catalog lesson as the jasmine guide. A 2025 review supplies the composition numbers: citronellol 30–40%, geraniol 20–30%.
Material guide · 42 2023-08-26 12 min read Material guide: cashmeran — the 48-hour musk, the family's sprinter CAS 33704-61-9. The database calls it musk indanone, the trade calls it Cashmeran (IFF), the papers call it DPMI — three names, one molecule. Spicy, musky, woody, clean, and its 48 hours of longevity run far shorter than the series' other musks. 38 suppliers, a semi-solid to solid. A 2024 weight-of-the-evidence assessment concluded it is not expected to cause endocrine effects; a 2013 chiral-analysis study adds the reminder that five polycyclic musks are all used industrially as racemic mixtures.
Material guide · 43 2023-08-30 24 min read Material guide: indole — fecal when strong, floral when weak, but not everyone makes the turn CAS 120-72-9. The database's odor field holds animal, floral, fecal and naphthyl at the same time. It makes up 1.07–4.21% of jasmine absolute and 2.6–9.9% of orange flower absolute. The strength field says evaluate at 1% or less — the lowest figure in the series. A 2024 fMRI study took the concentration-flips-the-face story into the brain: 12 participants who switch, 15 who don't. Another 2024 paper identified a second receptor that catches indole, Olfr205, and the key is a hydrogen bond. 53 suppliers, a white to amber yellow crystal.
Material guide · 44 2023-09-03 17 min read Material guide: methyl anthranilate — the grape soda note lives inside white flowers CAS 134-20-3. The odour field lists fruity, grape, orangeflower and neroli side by side. It sits at 9.00% in champaca concrete, 2.0–11.4% in orange flower water absolute and 4.90% in Egyptian jasmine absolute, yet it smells like grape soda. A 2020 study traced the 'foxy' aroma of Concord grapes to promoter indels in a single gene; a 2024 study found grapes, sweet orange and maize each build the same molecule by different routes. 88 suppliers, 88 hours substantivity, specific gravity 1.16 — heavier than water.
Material guide · 45 2023-11-15 13 min read Material guide: geranyl acetate — when a rose changes geraniol's clothes CAS 105-87-3. Add an acetyl group to geraniol and the rose note shifts toward pear, lavender and green floral. A 2003 study found the rose-petal enzyme RhAAT1 behind that step: it was expressed only in floral tissue and peaked at the stage of highest scent emission. 130 suppliers, 24 hours substantivity; practically insoluble in water and best kept refrigerated and tightly sealed.
Material guide · 46 2023-11-19 15 min read Material guide: Eucalyptus globulus oil — one botanical name, a tenfold range inside the bottle CAS 8000-48-4. Eucalyptus oil is not another name for eucalyptol but a natural mixture whose proportions change with origin, leaf age and plant part. In a 1995 study, leaf oils held 4.10–50.30% 1,8-cineole; a 2023 sample held 63.1%, while the European Pharmacopoeia medicinal oil specification requires at least 70%. 129 suppliers, high strength and very short substantivity; protect from heat and light and keep tightly closed.
Material guide · 47 2023-12-01 21 min read Material guide: dihydromyrcenol — one drop and the whole bottle is 1988 CAS 18479-58-8. The clean lime molecule behind a decade of men's fragrance and most of the laundry aisle. 53 suppliers, medium strength, 16 hours on a blotter. A 2009 rat developmental study set a NOEL of 500 mg/kg/day against an estimated human intake of 0.02 mg/kg/day, a margin of 25,000. A 2014 chamber study measured what indoor ozone does to it.
Material guide · 47 2023-11-23 15 min read Material guide: benzyl alcohol — fragrance, solvent and preservative system, one name with different jobs CAS 100-51-6. It has a mild rose-balsamic odour, yet formulators also use it as a solvent, solubilising agent or preservative excipient. A 2026 study found two petunia reductases that make benzyl alcohol and connected the pathway to benzyl acetate, benzyl benzoate and salicylic acid. Water solubility about 4.29%, 35 hours substantivity, 125 suppliers; store cool, dark, tightly closed and under nitrogen.
Material guide · 48 2023-12-05 24 min read Material guide: hydroxycitronellal — barely exists in nature, and lily of the valley depends on it CAS 107-75-5. The backbone of the muguet accord, and one of the 26 fragrance allergens the EU requires on the label. 53 suppliers, 218 hours on a blotter. In a 2016 Thai study of 312 consecutively patch-tested patients it was the third most common individual allergen at 3.8%, and 17.8% of positive patients read negative on the standard screening mixes. It ranks 9th in our 954-formula corpus at 16.9%.
Material guide · 49 2023-12-13 21 min read Material guide: benzyl salicylate — barely smells of anything, and can take a tenth of the formula CAS 118-58-1. Strength rated low, yet it holds 384 hours on a blotter. It ranks 11th in our 954-formula corpus at 16.7%, with a median dose of 9.47%, one of the heaviest uses in the top fifteen. A 2025 Plant Cell paper places it as an intermediate in plant salicylic acid biosynthesis; a 2026 in vitro study found it the strongest 11β-HSD2 inhibitor among 15 salicylate esters.
Material guide · 51 2023-12-29 18 min read Material guide: alpha-terpineol — what citrus turns into when it gets old CAS 98-55-5. 103 suppliers, with descriptors spanning pine, lilac, citrus and wood. In a 2026 simulated lemon juice system, thirteen of sixteen terpenoids convert into it — it is the terminus of citrus terpene chemistry. A second 2026 paper on the cinnamon-like aroma of Rougui Wuyi Rock Tea measured linalool suppressing it, dropping intensity from 5.83 to 2.00. Linalool happens to be its most frequent partner in our formula corpus.
Material guide · 52 2024-01-06 22 min read Material guide: ylang ylang oil — four different products sharing one CAS number CAS 8006-81-3 and 68606-83-7. One distillation cut into extra, I, II and III, and in the database grades I, II, III and cananga oil all share CAS 68606-83-7. This is the exact inverse of the Iso E Super case: that was one material spread across four CAS numbers, this is four products crammed into one. In a German study of 10,930 patients, ylang ylang topped twelve essential oils at 3.9%.
Material guide · 53 2024-01-14 20 min read Material guide: cinnamic alcohol — it cannot sensitise you; your skin turns it into something that can CAS 104-54-1. The backbone of the hyacinth accord, 79 suppliers, 371 hours on a blotter. It is a constituent of fragrance mix I, and in a Thai study of 312 patients it ranked first among the 26 individual fragrance allergens at 11.2%. The interesting part is that it has no structural alert for protein reactivity — a 2015 study using human liver microsomes showed it must be activated by air oxidation or metabolism first, and the process generated two highly sensitising epoxides not previously observed.
Material guide · 54 2024-01-22 19 min read Material guide: alpha-ionone — raise the concentration and it can get harder to detect CAS 127-41-3. 115 suppliers, violet and orris, 112 hours on a blotter. A 2025 study ran ten log-spaced concentrations across a large number of trials and found the human detection curve is non-monotonic, with reliable dips near 10⁻⁵ and 10⁻³·⁵. The same study found participants' trial-by-trial confidence matched their performance while their self-rated sense of smell did not.
Material guide · 55 2024-01-30 20 min read Material guide: gamma-undecalactone (aldehyde C-14) — it is not an aldehyde and it has no fourteen carbons CAS 104-67-6. The peach and apricot material, 119 suppliers, 338 hours on a blotter. Its common name gets it wrong twice: it is a lactone rather than an aldehyde, and its formula is C₁₁ rather than fourteen carbons — even the database appends "so-called". A 2026 study measured its MIC against Candida albicans at 112.5 µg/mL, while delta-undecalactone, one ring atom away, showed none at all.
Material guide · 56 2024-02-07 20 min read Material guide: musk ketone — four of its five siblings are banned; it survives on a purity specification CAS 81-14-1. The only nitro musk IFRA has not prohibited, and its Standard is a Specification rather than a restriction: it may be used only if it contains less than 0.1% musk xylene, because that one is already banned on environmental grounds (vPvB). 43 suppliers, vapour pressure 0.000012 mmHg. A 2000 zebrafish study put the embryo NOEC at 10 µg/L, and a decade of Korean indoor dust sampling still finds it among the dominant compounds.
Material guide · 57 2024-02-15 20 min read Material guide: ethyl vanillin — everyone says it is three times stronger than vanillin, and the database cannot tell them apart CAS 121-32-4. Vanillin plus one ethyl group, not found in nature, 76 suppliers. Its median dose across our 953-formula corpus is 0.50% against vanillin's 1.00% — the only measured trace supporting "stronger", because the database's strength field says the same sentence about both. Two 2026 studies put them side by side: against Aspergillus it did not win, and against pepsin the two are nearly tied.
Material guide · 58 2024-02-23 24 min read Material guide: omega-pentadecalactone (exaltolide) — a musk that grows in angelica root, and why smelling it faintly may not be your nose CAS 106-02-5. It appears in the 954-formula corpus under four different names, 31 formulas in total, median dose 3.00% — count by name and you miss it entirely. Its GHS is one statement; nitro-musk musk ketone carries six. It makes up 0.85% of angelica root oil. And a 2024 Givaudan study found that the key receptor for macrocyclic lactones is OR5A2, where a single P172L substitution cuts sensitivity about 50-fold and homozygous panelists have 40 to 60 times the detection threshold.
Material guide · 59 2024-03-02 25 min read Material guide: cyclamen aldehyde — the survivor of the muguet slot, living on a purity spec CAS 103-95-7. Its IFRA specification reads: cyclamen aldehyde should not contain more than 1.5% of cyclamen alcohol — and cyclamen alcohol has been on the prohibition list since 1980. Lyral, in the same slot, was banned in the EU in 2021; Lilial followed in 2022. This one is still standing, restricted to 0.95% in Category 4. A beginner demo formula posted on a forum warns not to double it, and the arithmetic says the author is right.
Material guide · 60 2024-03-11 27 min read Material guide: 1,8-cineole — the shortest longevity in the series, and the only material here that is also a prescription drug CAS 470-82-6. Its longevity record is 4 hours at 100%, the shortest across sixty material guides, and its vapour pressure of 1.9 mmHg is the highest. It is also marketed in Germany as a 200 mg capsule, and a 2024 trial of 522 people reports that early dosing cut disease burden by 38% — in an open-label, non-randomised study in which every author received funding from the manufacturer. Two case reports also exist: a six-year-old lost consciousness after topical application, and a three-year-old had CNS depression within thirty minutes of ingestion.
Material guide · 61 2024-03-19 26 min read Material guide: helional — five names in the corpus, nitrogen in the bottle, and the control that showed no sex difference CAS 1205-17-0. It appears in the 954-formula corpus under five names, 61 formulas combined (6.4%), with tropional alone accounting for 20 — search only for helional and you miss a third of them. The database's storage field says store under nitrogen, an instruction that appears in only 92 of the 1,232 materials carrying storage advice. Its GHS runs to seven statements including H317, may cause an allergic skin reaction. And the sperm-attractant story people cite belongs to bourgeonal; in a 500-subject study helional was tested alongside it and showed no difference at all.
Material guide · 62 2024-03-27 26 min read Material guide: Lilial — a top-fifteen material in the corpus, banned in EU cosmetics, and my database never mentions it CAS 80-54-6. It appears in 151 of 954 public formulas (15.8%) at a median dose of 6.00%, ranking 13th once solvents are removed. It has been banned in EU cosmetics since March 2022 — on a reproductive toxicity classification, H361, rather than sensitization. And in my database record the regulatory field is blank; that record will not warn you about anything. A 2024 Saudi analysis of 108 marketed products detected banned Lilial or Lyral in 97 of them.
Material guide · 63 2024-04-04 26 min read Material guide: benzaldehyde — 108 suppliers, four hours' longevity, and it shares a reaction with hydrogen cyanide CAS 100-52-7. The database's own synonym for it is "artificial bitter almond oil". It has 108 suppliers and lasts 4 hours — exactly the class that the "under eight hours means cheap" standard condemns. Its GHS carries H334, may cause allergy or asthma symptoms if inhaled, which appears in only 4 of the 369 database records with GHS data. Shelf life is 18 months rather than the usual 24, and it wants nitrogen. And a 2026 study confirms that bitter almond's almond smell and its hydrogen cyanide come from the degradation of the same precursor.
Material guide · 64 2024-04-12 26 min read Material guide: Vertofix (methyl cedryl ketone) — the only single molecule in the database that is woody, musk, amber and leather at once CAS 32388-55-9. The database calls it methyl cedryl ketone, IFF's trade name is Vertofix, and RIFM's safety assessment calls it acetyl cedrene — three names. Its odour field spans woody, vetiver, amber, leathery, musk and cedar, and across all 42,225 records only three carry woody plus musk plus amber plus leather together. The other two are not single molecules at all. The GC analyst in the last article said it "already was used to try and hide things" in a formulation; that odour field is why.
Material guide · 65 2024-04-20 26 min read Material guide: Aurantiol — a reaction product of two other materials, sold as a material, and the mass balance is exact CAS 89-43-0. It is the Schiff base of methyl anthranilate and hydroxycitronellal — the reaction the last article described as happening slowly in your bottle, except the manufacturer ran it first. The molecular weights add up to the decimal: 151.17 + 172.27 − 18.02 = 305.42. Longevity goes from the parents' 88 and 218 hours to 400. The database holds five members of this family from three houses, and two of them are built from aldehydes that are now banned in the EU.
Material guide · 66 2024-04-28 24 min read Material guide: Calone (watermelon ketone) — one of the highest longevity records in the database, and the number carries a greater-than sign CAS 28940-11-6. Its longevity record reads "> 600 hours at 10% in DPG". Of 2,027 longevity records only 17 exceed 400 hours, and this is one of them — measured in a tenfold dilution. Incidentally 206 records across the database carry a greater-than sign; those are lower bounds, not measurements. It is called watermelon ketone and is not found in nature, and a 2020 study measured real watermelon aroma as coming principally from C6 and C9 aldehydes and alcohols — structurally unrelated to this molecule. Someone in a thread said they bought 50 g, which is 1,099 five-gram trials.
Material guide · 67 2024-05-06 26 min read Material guide: phenethyl alcohol — a median dose of exactly 10.00%, matching what Arctander wrote sixty years ago CAS 60-12-8. It appears in 274 of 954 public formulas (28.7%), third only to linalool and benzyl acetate, and its median dose is 10.00% — the highest of the ten most common materials. Arctander wrote 5-10-20%. It is the heaviest ingredient in 48 formulas. Odour strength is only medium, yet substantivity runs 32 hours; water solubility is 22,000 mg/L, high enough to make rose water. A 2016 study traced how roses build it using deuterium labels, and found the dominant route changes with the season. A 2024 review explains why natural material is expensive: the molecule poisons the yeast that makes it.
Material guide · 68 2024-05-14 26 min read Material guide: Veramoss / Evernyl — one molecule under five trade names, and the database says it doesn't occur in nature (it's wrong) CAS 4707-47-5, atraric acid. Evernyl, Veramoss, Atralone, Phenomoss and Mousse de Metra are all the same material. It appears in 52 of 954 public formulas (5.5%), split across two names: 25 write veramoss, 27 write evernyl. The reason it exists is in IFRA Amendment 49 — oakmoss extracts are capped at 0.10% in Category 4, and this molecule has no standard at all. The database occurrence field reads 'not found in nature', but a 2020 study isolated it from a lichen. A crystalline powder melting at 143 °C, rated high strength, 400 hours at 10% dilution.
Material guide · 69 2023-12-21 27 min read Material guide: alpha-hexyl cinnamaldehyde — the jasmine molecule jasmine doesn't make, third most declared allergen, near the bottom in the clinic CAS 101-86-0. It appears in 157 of 954 formulas (16.5%) at a median dose of 8.00%, among the heaviest-dosed materials this series has covered. Its odour field says jasmin; its occurrence field says chamomile. GHS flags H317 for skin sensitisation, and a 2018 survey of 1,447 products across 131 households found it among the three most frequently declared allergens — while a 2007 study of 21,325 patch-tested patients put its sensitisation rate at 0.1%, near the bottom of the EU's 26. It differs from alpha-amyl cinnamaldehyde by one carbon, and that carbon moves the household IFRA limit by an order of magnitude.
Material guide · 70 2024-05-26 28 min read Material guide: isoeugenol — it just became the top fragrance allergen, because the ones above it were regulated away CAS 97-54-1. A 2020 analysis of German IVDK data from 2016-2018 reports that the allergen with the most positive reactions in fragrance mix I is no longer oakmoss absolute but isoeugenol. It did not become more dangerous; oakmoss and HICC were prohibited in the EU, and the same paper records fragrance mix I positives falling to a historical low of 5.4%. IFRA Amendment 49 caps it at 0.11% in Category 4, one ninetieth of the 9.9% allowed for the hexyl cinnamal of the previous piece. And the median dose across 954 public formulas exceeds that limit once diluted, because most of those formulas predate 2020.
Material guide · 71 2024-06-03 26 min read Material guide: dimethyl sulfide — the molecule people mean by "the smell of the sea", filed under onion and cabbage CAS 75-18-3. Eighty-one suppliers, and a molecular weight of 62.13 — the smallest molecule this series has covered. Boiling point 37.3 °C, below body temperature; flash point −36.7 °C; substantivity 4 hours; recommended smelling dilution 0.10% or less. All four are extremes for this series. It appears seven times across 954 public formulas, and all seven are pre-dilutions, working out to a median of 80 ppm neat. Not one of those seven is a marine fragrance: strawberry, mulberry, blueberry muffin, geranium, cream soap. It is genuinely the sea's signalling molecule — loggerhead turtles respond to it at 10 nmol/L, and not to cinnamon, jasmine or lemon.
Material guide · 72 2024-06-11 25 min read Material guide: phenylacetaldehyde — a three-month shelf life, and it caught moths in a field trap on its own CAS 122-78-1. Thirty-one suppliers, 57 of 954 formulas. Its shelf life is the shortest this series has met: three months, where most materials carry twenty-four. It spans nine formula genres, but florals take 66.1% of its appearances, against the corpus baseline of 35.4% — one of the most concentrated specialists in the set. A 2005 study identified 44 and 45 volatiles in two Gymnadenia orchids and found only 7 and 3 physiologically active; field trapping with phenylacetaldehyde alone caught moths carrying that orchid's own pollinia.
Material guide · 73 2024-06-19 24 min read Material guide: alpha-amyl cinnamaldehyde — the twin that never became a workhorse, and four columns explaining why CAS 122-40-7. One carbon from alpha-hexyl cinnamaldehyde, and the market chose the hexyl: 70 formulas against 157. Adding genre breadth this round sharpens the gap — the hexyl spans all fourteen genres with 32.4% in its largest, the amyl reaches twelve with 55.6%, well above the 35.4% baseline. Substantivity 256 hours against 400. Aquatic hazard H411 toxic against H412 harmful, and IFRA Category 9 therefore reads 1.5% against 19%. Four independent columns point the same way. A 1996 Danish study found both twins inside perfumes sold as natural.
Material guide · 74 2024-06-27 22 min read Material guide: allyl amyl glycolate — change the solvent and its no-effect level drops to a third CAS 67634-00-8. Forty-six suppliers, 58 of 954 formulas, median dose 0.67%. A 2006 cumulative irritation study in 129 human subjects did something rarely done: it tested one material in three vehicles. In diethyl phthalate its no-observed-effect level came out at 0.33%; in an ethanol-rich 1:3 vehicle it fell to 0.12% — same material, same subjects, nearly threefold. And perfume's vehicle is ethanol. Even finding the paper is a trap: this material's RIFM assessment is filed under allyl (3-methylbutoxy)acetate.
Material guide · 75 2024-07-05 22 min read Material guide: para-anisaldehyde — a third of cassie absolute, and studied as a citrus anti-mould agent CAS 123-11-5. Ninety suppliers, among the highest this series has covered. It appears in 60 of 954 formulas at a median dose of 2.25%. Its occurrence field carries an unusual figure: cassie absolute at 34.36% — a third of a natural absolute is this one molecule. In food science it plays a different role: a 2019 study found minimum inhibitory and fungicidal concentrations of 2.00 μl/ml against the two Penicillium species responsible for about 90% of citrus losses after harvest, by disrupting cell wall integrity and membrane permeability.
Material guide · 76 2024-07-13 25 min read Material guide: orris butter — what you buy is the percentage, not the material CAS 8002-73-1. Forty suppliers, melting point 40-46 °C — liquid only above body heat, among the highest-melting naturals this series has covered. And the database rates its odour strength as low. Both facts have one cause: a 2024 study comparing headspace with hydrodistillation on iris rhizomes found the hydrodistillate dominated by docosane at 45.79% plus fatty acids, with irone falling from 43.74-45.76% to 24.70%. It is a mass of fatty acids with the thing you want inside it. Which is why suppliers put the content in the product name: 15%, 8% — two bottles both called orris butter can differ twofold.
Material guide · 77 2024-07-21 24 min read Material guide: dihydro-beta-ionone — the odour field says woody, amber, cedar, and it lasts nine hours CAS 17283-81-7. Thirty suppliers. The odour field lists fourteen descriptors including woody, mahogany, amber and cedar, which sounds entirely like a base material. Its substantivity is 9 hours at 100%, ranking 181st shortest among the 800 materials with 20+ suppliers and a substantivity record. Someone put it at 8% of their first perfume as a woody backbone, which will not go as planned. And the database's occurrence field misses an important source: a 2022 paper opens by calling it a characteristic aroma compound of Osmanthus fragrans, and osmanthus is not in that field.
Material guide · 78 2024-07-29 23 min read Material guide: cis-3-hexenyl acetate — the smell of cut grass, and it is a plant's alarm signal CAS 3681-71-8. A hundred and three suppliers, among the highest counts in this series. Its substantivity field reads "< 4 hours at 100%" — with a less-than sign, and the shortest this series has met. It appears in 79 of 954 formulas at a median dose of 0.60%. Its role in nature is far better known than its role in perfume: a 2008 study exposed poplar saplings to naturally wound-emitted concentrations of it, and when those leaves were later fed on by gypsy moth larvae they carried higher jasmonic acid and had their defence genes primed. The smell of cut grass is a warning, and trees listen.
Material guide · 79 2024-08-06 22 min read Material guide: octyl acetate — one record describes it as jasmine and as mushroom CAS 112-14-1. Fifty-five suppliers. Its odour type field says floral, while its odour field reads green, earthy, mushroom, herbal, waxy, fruity, apple. Within that same record, one supplier's note says "Odor: Jasmine", another says floral, herbaceous, fruity, and the database's own description is green, earthy, mushroom, herbal, waxy. This is not a data error; it is what this molecule is like. It is simultaneously a trace natural constituent of bergamot oil (0.07-0.20%), a major constituent of Boswellia occulta frankincense, and a synthetic adulterant that a 2022 study found in commercial frankincense oils.
Material guide · 80 2024-08-14 19 min read Material guide: hexyl salicylate — the strength field says low, and the median dose in formulas is 7% CAS 6259-76-3. Forty-two suppliers. The database rates its odour strength as low and lists its odour as fresh, herbal, orchid, green — it reads like a material you could skip. It appears in 57 of 954 published formulas at a median 7.05%, above 5% in 40 of them, and once at 84.3%. It is the kind of material you never notice on its own while it carries the weight of the formula. One warning: three near-neighbours share most of this name in the database, and one of them is a sunscreen ingredient.
Material guide · 81 2024-08-23 22 min read Material guide: lavender oil — fougère at 7.3× baseline, and it almost never shares a formula with lavandin CAS 8000-28-0. Ninety-nine suppliers, among the most of any natural this series has covered. It appears in 55 of 954 published formulas at a median 6.06%. The number that identifies it is the genre: 29% of the formulas containing it are fougères, against a corpus baseline of 4% — 7.3×, the strongest genre concentration this series has measured. Its most frequent companion is coumarin, at 55%. As for its close relative lavandin, only one formula in 954 uses both. The database also gives their substantivity as 12 hours and 216 hours, an eighteenfold gap I cannot account for.
Material guide · 82 2024-08-31 25 min read Material guide: Tonalide (AHTN) — the most discussed polycyclic musk, and not the most used one CAS 21145-77-7, filed in the database under the name "musk tetralin". It melts at 53 to 54 °C, which is why it arrives in chunks. Thirty-two suppliers, and at least five trade names sell the same molecule. Its GHS classification carries both acute and chronic aquatic toxicity at Category 1, a pairing few fragrance materials hold. But the corpus numbers do not match the volume of environmental discussion: across 954 published formulas, galaxolide under all spellings appears in 110 and AHTN in 17, a ratio of 6.5 to 1. And in a 2023 zebrafish study, AHTN came out better than galaxolide on thyroid disruption.
Material guide · 83 2024-09-08 23 min read Material guide: guaiacol — the flavour field literally says bacon, and it appears in five corpus formulas CAS 90-05-1. Sixty-one suppliers. Someone on a forum joked that for hunting you should add guaiacol because it smells like bacon; checking the database, that is correct — its flavour field says bacon in so many words. Strength is rated high, with evaluation recommended at 1% or less, and substantivity runs 280 hours. It melts between 28 and 32 °C, so it is solid in winter and liquid in summer, and the appearance field itself hedges with "oily liquid to solid". The natural occurrence list is absurdly long: asparagus, beer, butter, cheese, cinnamon, cocoa, coffee, popcorn, roasted peanut. Two papers explain why — it is a product of burning and roasting, and it is often locked up as a glycoside that only an enzyme can release.
Material guide · 84 2024-09-16 20 min read Material guide: triethyl citrate (TEC) — not a fragrance material, and the bottle you will empty fastest CAS 77-93-0. Fifty-four suppliers. The database files it not as a fragrance material but under "carrier solvents/diluents for flavors and/or fragrances", and its strength field reads none. It is not actually odourless — the odour description field says "odorless to mild fruity wine". It melts at −46 °C, so it is a liquid at any room temperature, and the thick thing is never the solvent. It is also food additive E1505, a whipping aid for egg white, and a plasticiser for plastics. What separates it from DPG is polarity: logP 0.10, water solubility 6.5 g per 100 mL. And in the corpus it loses badly — DPG appears 445 times, TEC 5.
Material guide · 85 2024-09-24 21 min read Material guide: isobutyl quinoline — one molecular formula, five records, and a tenfold spread in recommended evaluation strength The database holds five records all called some version of isobutyl quinoline. Every one is C13H15N with a molecular weight of 185.27, and every one has a different CAS number. Their odour fields differ (some read animal, leather, tobacco; one reads earthy, rooty, nutty, oakmoss), their strength ratings differ (medium and high), their recommended evaluation strengths range from 1% to 10%, and supplier counts run from zero to twenty-two. Someone on a forum wrote Pyralone and IBQ as one item. Those are CAS 65442-31-1 and 93-19-6, and the supplier notes the database itself quotes describe them separately.
Material guide · 86 2024-10-02 20 min read Material guide: hexanal (aldehyde C-6) — 107 natural sources, and almost nobody writes it into a formula CAS 66-25-1. Seventy suppliers. Its natural occurrence field lists 107 sources including apple, banana, blueberry, butter, cabbage and bread, so the forum's "it's there almost on all fruits" points the right way. Yet only 1.6% of the corpus's 122 fruity formulas contain it, against a 1.4% baseline — no enrichment at all. The reason sits in two other fields: strength rank 3 with evaluation recommended at 1% or less, and a substantivity of just 4 hours, the shortest of the 86 materials this series has covered. Its flash point of 32 °C is worth noting too. It is not overlooked in formulas; it finishes its job and leaves.
Material guide · 87 2024-10-10 19 min read Material guide: veratraldehyde — the database calls it a heliotropin replacer, and it appears once in 954 formulas CAS 120-14-9. Fifty-two suppliers. Yellow crystalline needles melting at 42 to 45 °C, so it arrives as a solid. Substantivity 400 hours, medium strength, evaluation recommended at 10% or less. Its notes field holds a single phrase: heliotropin replacer. It has five natural sources, one of them Bourbon vanilla. What is interesting is that it barely exists in published formulas — once in 954 — while in a crème brûlée formula posted this week it is the fourth-largest line at 85 parts, in a formula that also contains heliotropin.
Material guide · 88 2024-10-18 20 min read Material guide: sotolon — the database calls it caramel furanone, which is why I could not find it last round CAS 28664-35-9. Forty-one suppliers. It is one of only nine materials among 42,225 database records recommended for evaluation at 0.01% or less. Its substantivity reads > 400 hours at 3% in propylene glycol, a lower bound rather than a measurement. Concentration decides what it is: fenugreek and curry at high levels, maple syrup, caramel and burnt sugar at low ones. Its natural occurrence field lists coffee, fenugreek seed, buckwheat honey, maple, pineapple, sake, sherry, Virginia tobacco and rice wine. And the fact that this database does not file it under the name sotolon is what led me to publish a wrong conclusion last round.
Material guide · 89 2024-10-26 20 min read Material guide: Lyral (HICC) — the database calls it leerall, the EU banned it, and the supplier field still says 40 CAS 31906-04-4. Banned in EU cosmetics since 2021 on grounds of contact sensitisation. This site's database files it under the name leerall, with Lyral in the head synonym field. Substantivity 400 hours; odour reads floral, muguet, cyclamen, rhubarb, woody. It appears in 50 of 954 published formulas at a median dose of 4.57%, which is not a trace. And its GHS field lists only harmful if swallowed, mild skin irritation and eye irritation — no sensitisation classification, despite sensitisation being precisely why it was banned. Its natural occurrence field also manages to say both "not found in nature" and "sage oil @ 0.10%".
Material guide · 90 2024-11-03 20 min read Material guide: DPG (dipropylene glycol) — the one that appears 445 times in the corpus, and it isn't a fragrance material CAS 25265-71-8. Thirty-seven suppliers. This series covered TEC in article #84; this is its counterpart. Across 954 published formulas DPG appears as a standalone entry 445 times and TEC 5 — the default diluent of published formulas is this one. Its logP is −0.60 against TEC's 0.10, and it is fully miscible with water, so the division of labour between them is polarity: DPG for hydrophilic work, TEC for lipophilic resins and concretes. Its strength field says none, while its odour description reads slight alcoholic. The substantivity field gives it 400 hours, for a diluent. The notes field is one sentence: a very good fragrance diluent and quencher, but it is synthetic.
Material guide · 91 2024-11-11 23 min read Material guide: ethanol — the one that is 80% of the finished product, and it has a smell CAS 64-17-5. Forty-one suppliers. This is the third solvent in this series and by far the largest by volume: about 76% of a finished EDP. The database files it as a carrier solvent, diluent and extraction solvent rather than a fragrance material. But its odour strength field reads medium and its odour field reads alcoholic, ethereal, medicinal — it is not an odourless background. Its substantivity field reads < 1 hour, the first upper bound this series has met after a run of > lower bounds. Its vapour pressure of 44.6 mmHg is the highest of any material covered here and its flash point of 9.44 °C the lowest. And its grades field lays out the 190 versus 200 proof question directly.
Material guide · 92 2024-11-19 20 min read Material guide: ethyl maltol — the solubility field unusually gives four actual percentages CAS 4940-11-8. Seventy-five suppliers. The database files it as a flavour enhancer and flavouring agent, not a fragrance material. It earns an entry because its solubility field does something rare in this database: it gives numbers. Alcohol 12%, benzyl alcohol 10%, phenethyl alcohol 5%, propylene glycol 5.5%. For its relative maltol the same field gives propylene glycol 2.8% and glycerin 1.2%, with no figure for alcohol at all. The difference comes from melting point: 89 to 93 °C against 159 to 162 °C. Strength rank 3, evaluation recommended at 5% or less, substantivity 360 hours at 20% in benzyl alcohol, and not found in nature.
Material guide · 93 2024-11-27 17 min read Material guide: amber naphthofuran (Cetalox), same formula as Ambroxan under a different CAS CAS 3738-00-9, 31 suppliers. Its formula, molecular weight, logP and estimated water solubility all match ambroxan (6790-58-5) exactly, and the PubChem IUPAC names differ only by a stereodescriptor prefix at the front. The melting range is where they part: ambroxan melts over 74-75 C, this one over 75-85 C. FEMA and the Council of Europe give both the same numbers (3471, 10514) while CAS splits them in two. The database's own note reads 'Ambrox replacer'. Recommended evaluation strength is 10 percent or less, an order of magnitude looser than ambroxan's 1 percent, yet both carry strength rank 3.
Material guide · 94 2024-12-05 14 min read Material guide: IPM (isopropyl myristate), the one with a vapour pressure 97 times below DPG CAS 110-27-0, 54 suppliers. The database files it as a carrier solvent and diluent for fragrances, and its odour strength field reads none. It earns an entry because of three fields together: vapour pressure 0.000329 mmHg (97 times below DPG), logP 7.20 (the most lipophilic of the common carrier solvents), and a melting point of 2-3 C. The first two govern how it behaves in nozzle residue; the third decides whether it sets in winter. Oral LD50 is above 16000 mg/kg in rat and 49700 in mouse. And it appears in only 4 of 954 published formulas.
Material guide · 95 2024-12-13 16 min read Material guide: laevo-rose oxide, sharing a FEMA number with the racemic version while FLAVIS splits them CAS 3033-23-6, the (2S,4R) configuration, 8 suppliers against 77 for the racemic version. Its physical fields match the racemic almost exactly: molecular weight, logP 2.90, specific gravity, refractive index and vapour pressure are all identical. Three things differ. The odour field adds metallic and powdery; the substantivity field reads 388 hours where the racemic reads greater than 8, measured under entirely different conditions; and FLAVIS gives it its own 13.170 while FEMA 3236 and Council of Europe 2269 are shared with the racemic. It appears 4 times in 954 published formulas.
Material guide · 96 2024-12-21 17 min read Material guide: para-cresol, what the forum probably means when it calls ylang ylang faecal CAS 106-44-5, 25 suppliers. The database's recommended evaluation strength is 0.10 percent or less, the lowest band in the whole library. The odour field reads phenolic, narcissus, animal, mimosa. It is recorded in cananga oil from China at 0.27 percent, cananga being the same genus as ylang, and it also turns up in coffee, butter, blackcurrant buds and oolong tea. The toxicity field is what makes it worth an entry: rat oral LD50 207 mg/kg and rabbit dermal 301 mg/kg, where ylang ylang essential oil itself reads greater than 5000 for both. Same plant, and the constituent sits more than 24 times below the whole oil. Substantivity 400 hours; melting point 32 to 35 C, so it crosses back and forth around room temperature.
Material guide · 97 2024-12-29 16 min read Material guide: 2-acetyl pyrazine, evaluate at 0.10% or less, and most people smell it neat first CAS 22047-25-2, 80 suppliers. The strength field says very high, wording that is uncommon in this library, and the recommended evaluation strength is 0.10 percent or less. It is a white crystalline powder rather than a liquid, melting at 76 to 78 C. The odour field runs from popcorn and corn chip through bread crust, chocolate, hazelnut and coffee. Everything in its occurrence field has been heated: roasted almond, bread, cocoa, coffee, filbert, peanut, popcorn, potato chip, sesame oil. And it appears twice in 954 published formulas, once of them tagged as a 0.1 percent dilution.
Material guide · 98 2025-01-06 18 min read Material guide: thyme oil, white and red, one CAS and two FEMA numbers White thyme oil has 55 suppliers, red thyme oil (Spain) 38 and red thyme oil (India) 18, and all three share CAS 8007-46-3. FEMA gives white 3065 and red 3064. The substantivity fields are measured under matching conditions (both neat) and differ by 2.1-fold: white 83 hours, red 172. The appearance differs too, white being colorless to pale yellow and red amber to orange red. Thyme has six chemotypes, and the thymol content recorded across origins in this database runs from 0.2 to 71.84 percent. Also, the notes field on the white thyme record describes an entirely different plant, which is a clear cataloguing error.
Material guide · 99 2025-01-14 15 min read Material guide: phenethyl salicylate, one of the lowest vapour pressures in the library, and the strength field says low CAS 87-22-9, 33 suppliers. Its vapour pressure of 0.000002 mmHg is the lowest of any odorous material in this database with 25 or more suppliers, 22 million times below ethanol. And its strength field reads low, at strength rank 1, the bottom band in the library. Both being true at once is exactly what separates lasting a long time from having presence. It is a white crystalline powder melting at 39 to 41 C, with 232 hours of substantivity at 20 percent in dipropylene glycol. It occurs naturally in Tahitian gardenia and plumeria. And Arctander's verdict on it: this material is very well known, but not extensively used.
Material guide · 100 2025-01-22 16 min read Material guide: isoambrettolide, the second most-supplied macrolactone, and the notes field says it covers alcohol CAS 28645-51-4, 43 suppliers, fifth among the database's musk-type materials. Its first synonym reads hexadec-9-en-1,16 lactone, so the name says lactone outright and the formula C16H28O2 agrees. Unlike most musks at strength rank 3, this one reads medium, rank 2, evaluated at 10 percent or less, with 248 hours of substantivity. The occurrence field says not found in nature, despite the name pointing at ambrette seed. And the notes field carries a line I have not seen anywhere else in the library: it can be used to tone down the smell of alcohol.
Material guide · 101 2025-01-30 13 min read Material guide: Floralozone, the forum says ozonic and the database's controlled term is marine CAS 67634-14-4, 31 suppliers. The database calls it ozone propanal, with floralozone (IFF) as its first synonym. Its odour type is marine while the first word in its odour field is ozone. That gap is itself worth recording: ozonic does not exist among the 169 controlled odour types, and the marine slot is where it lives. Strength reads medium, evaluated at 10 percent or less, substantivity 80 hours, not found in nature. The notes field is four words: gives good body.
Material guide · 102 2025-02-08 15 min read Material guide: acetaldehyde, 94 suppliers and it boils at room temperature CAS 75-07-0, 94 suppliers, among the best-supplied materials in the library. Boiling point 20 to 21 C, flash point -40 C, vapour pressure 902 mmHg at 25 C, and a GHS statement of H224 extremely flammable. Its storage field reads refrigerate in tightly sealed containers, which 145 records do, but this one for a different reason: it boils above room temperature. Its substantivity field reads less than 1 hour, also the shortest. And its occurrence field records 265,926 ppm in beer, which is 26.6 percent. Evaluate at 0.10 percent or less.
Material guide · 103 2025-02-16 16 min read Material guide: benzyl benzoate, classified by the database as both a fragrance material and a carrier solvent CAS 120-51-4, 84 suppliers. The database's category field reads flavor and fragrance agents, carrier solvents, making it one of the few materials carrying both roles. Its strength field says low at rank 1, the bottom band, while its substantivity is 322 hours. The melting point is 18 to 21 C, so it sets indoors in winter. The solubility field carries measured figures that are rare in this library: 1 kg dissolves 450 g of musk ambrette, 280 g of musk xylol and 205 g of musk ketone. And it makes up 57 to 61 percent of cabreuva oil.
Material guide · 104 2025-02-24 18 min read Material guide: agarwood oil, a wound response with twice as many suppliers for its imitations CAS 94350-09-1, 26 suppliers. The database's note is blunt: this oil is water distilled from fungus infected wood of the Aquilaria tree. Two 2026 papers give the scale, one identifying 83 volatiles in agarwood essential oil with sesquiterpenes at 66.27 percent, the other identifying 118 agarwood-characteristic sesquiterpene skeletons plus 2-(2-phenylethyl)chromones. Its odour field carries ten words including sandalwood, leathery and tobacco, none of which appear on the compounded base (41 suppliers) or the replacer (16). And its odour description field carries a line saying almost all natural oud is adulterated at source.
Material guide · 105 2025-03-04 15 min read Material guide: Helvetolide, an -olide that is not a lactone, with two database fields contradicting each other CAS 141773-73-1, 14 suppliers. The database calls it musk propanoate, with helvetolide (Firmenich) as its first synonym. Its formula C17H32O3 has three oxygens, so it is an ester but not a cyclic one, which makes the -olide suffix misleading here. The strength field reads medium at rank 2 while substantivity reads greater than 336 hours. The odour description carries an unusually precise positioning: olfactively between ambrettolide and ethylene brassylate, with a fruity pear aspect. The solubility field even carries real dosage ranges, 0.5 to 5 percent in fine fragrances. And its natural/synthetic field says natural while its occurrence field says not found in nature.
Material guide · 106 2025-03-12 15 min read Material guide: BHT, the antioxidant everybody tells you to add, and the database gives it an odour type CAS 128-37-0, 52 suppliers. The category field reads antioxidants and preservatives for fragrance and flavor, and its odour type is phenolic, its odour field phenolic and camphoreous, its strength low at rank 1. Substantivity is 400 hours at 20 percent in dipropylene glycol, the ceiling value in this library, meaning it does not leave. It melts at 70 to 73 C, so it is a white crystal rather than a liquid. Water solubility 0.6 mg/L and logP 5.30 mean it needs ethanol or an oil phase. Its only GHS statement is H410, very toxic to aquatic life with long lasting effects. And its occurrence field carries two entries: garlic bulb, and rue oil from China at 0.05 percent.
Material guide · 107 2025-03-20 19 min read Javanol: the supplier says "unprecedented substantivity", and the substantivity field gives it the same number as sandalwood oil sandal cyclopropane (CAS 198404-98-7), Givaudan's Javanol, 14 suppliers. The supplier blurb claims "unprecedented power and substantivity". The database supports the power half: of 29 sandalwood-odour materials, only 3 read `high` in the strength field, and this is one of them. It cannot check the substantivity half. The field reads 400 hours — and of 2,027 records with a substantivity value, 334 (16.5%) read exactly 400, with only 17 above it. Sandalwood oil itself reads 400. Its assay floor is also 85%, marked "sum of isomers", which puts it in the bottom 3.7% of well-supplied materials.
Material guide · 108 2025-05-23 19 min read Material guide: benzophenone — the supplier calls it "very faint" and the substantivity field says 394 hours CAS 119-61-9, 41 suppliers. The odour field reads balsamic, rose, metallic, powdery, geranium — while the supplier's own description is "very faint powdery-rosy geranium-like odor". Faint plus 394 hours puts it in a class you can count: of the 1,193 well-supplied materials that have both a strength and a substantivity value, 189 (15.8%) are low or medium strength with 350+ hours. Vanillin, patchouli oil, coumarin and sandalwood oil are all in it, and that class does the volume work in a formula. It is also a crystalline powder melting at 47–51 °C, its GHS field carries H351, and its own storage field asks to be kept away from light.
Material guide · 145 2025-03-28 14 min read Material guide: geranyl nitrile — made to replace citral, and retired itself CAS 5146-66-7, 20 suppliers, sold by IFF as Citralva. Its category field reads 'information only not used for fragrances or flavors', and its cosmetic uses field says both 'not used anymore' and 'perfuming agents' — two contradictory statements inside one cell. The evaluation field is honest: citrus, lemon, nitrile, aldehydic, metallic. Neither 'nitrile' nor 'metallic' is a compliment. It exists because citral is unstable in alkaline media and nitriles are not. But nitriles have a problem of their own — Kaplita and Smith open their 1986 paper by noting that many, but not all, aliphatic nitriles undergo hepatic biotransformation in mice and rats to release free cyanide, and that the mechanisms remain in doubt. Substantivity 56 hours, vapour pressure 0.025 mmHg.
Material guide · 146 2025-04-05 14 min read Material guide: WS-23 — the first strength rank 1 material in this series, and that is the whole point of it CAS 51115-67-4, 25 suppliers, FEMA 3804. Its strength field reads 'low', rank 1 — nearly all of the hundred and forty-odd materials I have written up are rank 3, and this one is the opposite extreme. The notes field explains why: 'physiological cooling agent used in food; its effect is similar to that of menthol but without the strong minty flavour.' It separates the cooling sensation from the smell. And that separation has a basis at the receptor level — Sherkheli and colleagues noted in 2010 that known TRPM8 agonists like menthol and icilin cross-activate TRPV3 and TRPA1, while the menthol derivatives they characterised are selective for TRPM8 and do not activate the other thermo-TRPs. Its evaluation concentration is 25%, and the database holds only 14 distinct evaluation concentrations.
Material guide · 147 2025-04-13 13 min read Material guide: styralyl acetate — it is in 8.2% of formulas, and the corpus calls it by two names CAS 93-92-5, 77 suppliers, FEMA 2684. It appears in 78 of 954 formulas, and the corpus calls it both styrallyl acetate and gardenol — the second being what the database's synonym field says. The odour field reads green, leafy, gardenia, rhubarb, musty, fruity, seedy, berry, and one evaluation contains a rare piece of self-denial: 'strong, radiant, herbal-green-fruity, floral similar to gardenia, not tenacious.' Its substantivity really is only 8 hours, and its vapour pressure lands in the heart band I computed, whose median is 24 — this one sits at the short end. And there is something the fields never mention: it is chiral, and what you buy is a racemate.
Material guide · 148 2025-04-21 17 min read Material guide: cis-3-hexenyl salicylate — the worst self-contradiction in a boiling point anywhere in the database CAS 65405-77-8, 51 suppliers. Its boiling point field carries both 145 °C @ 5 mmHg and 394 °C @ 760 mmHg. Twenty-seven materials in the database register a boiling point at both of those pressures; the median gap between them is 147 °C, with quartiles at 126 and 164. This one is 249 °C, the largest in the database, 60 °C beyond the runner-up. Working back from the median puts it near 292 °C at atmospheric pressure, and its saturated analogue hexyl salicylate is registered at exactly 290 °C. In odour it is a bridge between two families: the cis-3-hexenyl half gives green leaf, the salicylate half gives soft floral and diffusion. It appears in 73 of 954 formulas at a median of 1.79%. Its only registered natural occurrence is witch hazel leaf oil at 0.01%.
Material guide · 149 2025-05-03 18 min read Material guide: perilla alcohol — two of its numbers look wrong, and it is also a drug in clinical trials CAS 536-59-4, 12 suppliers, cleared by JECFA and FEMA GRAS. It is limonene hydroxylated at C7, and it smells green, cumin, spicy, cardamom, orange peel. Its boiling point field carries 119 °C @ 11 mmHg alongside 93 °C @ 760 mmHg; a reduced-pressure boiling point cannot exceed the atmospheric one, and of the 1,258 materials registering both, only two commit that error. Its substantivity reads 269 hours, while its isomer laevo-carveol, same formula C10H16O, same molecular weight 152.23, and twice the vapour pressure, reads 51 hours. Linalool in the same family reads 12 hours, geraniol 60, citronellol 56. This one runs about four times longer than its family predicts. Outside perfumery, highly purified perillyl alcohol has been through a phase I intranasal trial in recurrent glioblastoma.
Material guide · 150 2025-05-11 15 min read Material guide: methyl cedryl ketone (Vertofix) — the corpus calls it by five names, and the database's official one finds a third of them CAS 32388-55-9, 71 suppliers. Its odour field puts woody, vetiver, amber, leathery, musk and cedar on a single line, six words that amount to a whole woody-amber accord. The corpus of 954 formulas calls it by five names: vertofix 50 times, methyl cedryl ketone 26, acetyl cedrene 7, vertofix coeur 3. Merging four of them puts it in 86 formulas, 9.0% of the corpus, at a median dose of 5.44%. Counting only the database's official name gives 26 and misses 60. Its substantivity reads 400 hours, and 400 is the database's bucket label for very long; but this material's vapour pressure is 0.000084 mmHg, in the bottom quarter of that bucket, so here the 400 is credible. It is made by acetylating the cedrene in cedarwood oil, and its occurrence field reads not found in nature. Both of those are true.
Material guide · 151 2025-05-19 16 min read Material guide: nutmeg oil — same tree as mace, and the human poisoning record is filed under the other one CAS 8008-45-5, 117 suppliers. It comes from the same tree as the mace oil I wrote up earlier, Myristica fragrans, from two different tissues: nutmeg is the kernel, mace is the red aril wrapped around the seed. Put the two records side by side and the most important difference is not in the odour but in the toxicology field. Nutmeg oil carries only an oral rat LD50 of 2,620 mg/kg. Mace oil carries a rat figure of 3,640 mg/kg plus a human one: oral TDLo 400 mg/kg, with hallucinations, distorted perceptions, toxic psychosis and cardiac arrhythmias. The famous poisoning cases involve nutmeg, yet the human data sits on the 34-supplier mace record rather than the 117-supplier nutmeg one. Both records also give occurrence as nutmeg seed, while mace's own definition field says it is the layer wrapped around the seed: two fields of one record disagreeing. Its optical rotation is registered at +8 to +30, a range wide enough to work as a fingerprint of origin.
Material guide · 152 2025-05-31 17 min read Material guide: Triplal — an 8-hour green aldehyde that becomes a 268-hour one once you attach an amine CAS 68039-49-6, 54 suppliers. The database's official name is 2,4-ivy carbaldehyde; perfumers write triplal. The corpus calls it by three names, which merge to 90 formulas at a median dose of 0.60%. It is strength rank 3, recommended for evaluation at 10% or less, with a substantivity of 8 hours and a vapour pressure of 0.578 mmHg: a textbook top-note green aldehyde. What makes it interesting is that the database also holds two of its derivatives. Condensed with methyl anthranilate as a Schiff base it reads 268 hours; with the ethyl ester it reads 400 hours at a vapour pressure of 0.000001. Same aldehyde, one amine attached, and the substantivity goes from 8 hours to 268. This is the pro-fragrance idea: the Schiff base hydrolyses slowly back in the presence of water, releasing both the aldehyde and the anthranilate. Its storage field also says keep under nitrogen, with a shelf life of only 12 months.
Material guide · 153 2025-06-08 15 min read Material guide: Aldehyde C-16 — not an aldehyde, not sixteen carbons, and not in strawberries CAS 77-83-8, 63 suppliers. The database's official name is strawberry glycidate 1 (aldehyde C-16 (so-called)), and its head_synonym carries the real chemical name: ethyl methylphenylglycidate. It is C12H14O3, twelve carbons, an epoxy ester rather than an aldehyde. Its occurrence field reads not found in nature, so the most famous strawberry material in perfumery is absent from strawberries. Its storage field calls for refrigeration, which only 11.8% of materials in the database do, and its shelf life is 12 months where most read 24. The three-membered ring is the likely reason. Two toxicology studies were run on it specifically, in 1978 and 1981, and both titles call it strawberry aldehyde. In the corpus it appears in 35 formulas at a median dose of 1.43%, and 24 of those also contain aldehyde C-14: the two travel together 69% of the time.
Material guide · 154 2025-06-16 16 min read Material guide: Verdox — one ring position away from Vertenex, and every physical field in the database is the same CAS 88-41-5, 52 suppliers. The database calls it green acetate; perfumers write Verdox. Merging the spellings puts it in 75 formulas at a median dose of 5.00%. It is 2-tert-butylcyclohexyl acetate, and it has a para sibling: Vertenex, CAS 32210-23-4, 4-tert-butylcyclohexyl acetate. Both are C12H22O2, both weigh 198.31, both have a 25 °C vapour pressure of 0.103 mmHg, both list a substantivity of 8 hours, and both are strength rank 2. The only physical fields that differ are the boiling point, 221 against 228 °C, and logP, 3.60 against 3.40. Their odour types read fruity and woody: Verdox is green apple, Vertenex is cedar. Everything this database can measure is identical, and the one thing that differs is the reason you would buy either of them.
Material guide · 155 2025-06-24 16 min read Material guide: cananga oil — it shares a CAS number with ylang's three grades, and its specific gravity range does not overlap theirs CAS 68606-83-7, 40 suppliers. That CAS number is also the one carried by ylang ylang grades I, II and III, so matching by CAS collapses all four into one material. The physical fields disagree. Cananga's specific gravity runs 0.906 to 0.923; ylang complete oil runs 0.948 to 0.968, and the two ranges do not overlap. Its optical rotation is -15 to -30 against ylang III's -60 to -40, which does not overlap either. The odour field is blunter still: cananga carries animal and leathery, and no ylang record carries either. It is the same plant, Cananga odorata, in its Java-cultivated form, water distilled rather than steam distilled, with a substantivity of 116 hours. This is the exact inverse of my last article: Verdox and Vertenex have different CAS numbers and identical physical fields; this pair has the same CAS number and different physical fields.
Material guide · 156 2025-07-02 13 min read Material guide: lemon oil — three words in the odour field, five in the notes field CAS 8008-56-8, 74 suppliers, FEMA 2625. Its odour field reads citrus, lemon, lemon peel: three words, where materials with 50 or more suppliers carry a median of eight. That is not a sloppy record. It is a material whose name is already its own descriptor, so no other word is needed to say what it smells like. The notes field is equally short: Do not use on skin, five words about furocoumarin phototoxicity. Its substantivity is 4 hours, among the shortest of the corpus's top fifty materials, and its optical rotation of +57 to +65.5 comes from the 90-plus percent d-limonene. Its shelf life is only 12 months. The corpus uses it in 127 formulas at a median dose of 4.44%.
Material guide · 157 2025-07-10 18 min read Material guide: folded sweet orange oil — 122 suppliers, more than the whole oil, and one record covering 5-fold to 50-fold CAS 8008-57-9, 122 suppliers, more than sweet orange whole oil's 99 and the most-supplied citrus record in this database. Its solubility field opens the market up by accident: Orange Oil 5 X, 10 X, 20 X, Italian 5 Fold and 10 Fold, Folded 5 fold to 20 fold, and Orange Essential Oil 50 Fold. One record covers every product from 5-fold to 50-fold. And the fold factor has an arithmetic ceiling: if terpenes are a fraction f of the crude oil, removing only terpenes cannot exceed 1/(1-f). At 90% terpenes that is 10-fold, at 95% it is 20-fold, and a 50-fold oil requires a crude oil that was 98% terpenes. Its registered optical rotation is +91 to +78, while fully deterpenated sweet orange reads +11 to +24, so that interval plainly cannot cover a 50-fold product. Its substantivity field is empty, where the whole oil reads 140 hours and the terpeneless one 212.
Material guide · 158 2025-07-18 15 min read Material guide: longifolene — a pure compound with five unusable fields CAS 475-20-7, 16 suppliers, C15H24. It is a single compound, so its refractive index, specific gravity and optical rotation should each be a constant plus a little room. In practice the refractive index reads 1.42000 to 1.60000, thirty times the database's median width; the specific gravity reads 0.93000 to 1.11000; the optical rotation reads +14 to +54, forty degrees wide. All three have round endpoints. The melting point field says 156.20 °C while the appearance field calls it a liquid, and that temperature sits above its own boiling point of 150 to 151 °C at 36 mmHg. The assay field reads 95.00 to 100.00, the database's default template. Meanwhile its own structural isomer (−)-isolongifolene has 11 suppliers and a specification thirty times tighter. It appears zero times in 954 formulas. But it is a real material: a sesquiterpene from turpentine, given a full RIFM safety assessment in 2019, and in 2025 engineered into fungi to attract and kill mosquitoes.
Sourcing · 14 2024-02-19 22 min read How do you afford this hobby — the biggest lever is not what you buy, it is how much you make at a time A thread asked how people afford this, and the 63 replies ranged from a few hundred dollars every other month to twenty-five thousand a year. Using median doses from 953 formulas: the same 10 g bottle makes one 100 g batch, or fifty 2 g trials. And 27 of the 79 most common materials are used above 5% — the recurring cost sits in the unglamorous ones, not the expensive bottles.
Sourcing · 15 2024-05-02 28 min read The materials you bought too much of: a table converting regret into trial counts A thread asked which material people bought too much of and barely used. Thirty-one replies named seventeen materials, with gram figures attached. I converted each against the median dose across 954 formulas: 10 g of indole makes 333 five-gram trials, 25 g of floralozone makes 1,250, and 250 g of benzyl butyrate makes over seven thousand. Thirteen of the seventeen have a median dose at or below 1%. And money is only part of the cost — 75.2% of database materials state a shelf life of two years or less, and 176 of the 263 IFRA standards were published or last revised in 2020 or later.
Safety · 3 2023-12-17 26 min read The "2027 ban list" isn't settled yet, and checking it takes three moves An 88-reply thread was worrying about a 2027 ban list of ten materials. Those ten touch 35.0% of our 954-formula corpus, but the list conflates two different things: an EU cosmetics ban already in force, and IFRA proposals still in consultation. IFRA's own page dates that consultation 12 December 2025 to 12 June 2026. A second thread found Iso E Super is restricted after all, and that searching the trade name on IFRA's site returns nothing.
Safety · 4 2023-12-25 25 min read How risky is DIY perfumery — the top-voted answer is checkably wrong, and the lowest-voted one is right Someone asked whether the hobby is bad for your health. Twenty-five replies. The 52-point answer said the only danger is your bank account; the 23-point one said almost nothing carries an IFRA Category 12 restriction. I pulled the full 51st Amendment Standards and counted: 177 standards list a Category 12 field, 40 of them carry a numeric limit, and seven of those sit below 0.25%. The larger point is that Category 12 was never the column to look at.
Safety · 5 2024-01-10 24 min read "Synthetics give me headaches, so I only use naturals" — that split does not predict risk Someone said chemicals give them headaches and nausea, so they stick to naturals. The data says otherwise: across 18,832 European patch test patients, the highest-scoring fragrance marker is Myroxylon pereirae at 6.5%, a natural resin. In a German study of 10,930 patients, ylang ylang oil topped twelve essential oils at 3.9%. And among IFRA-regulated materials, naturals are more often banned outright than restricted. Our own database cannot settle the question, which is worth saying too.
Safety · 6 2024-03-15 34 min read Running a fragrance activity for children: the sub said no, and some of its reasons are wrong A parent wanted a fragrance bar for her daughter's birthday party, ages 8 to 10, because party services charge around a thousand dollars — and asked for cleaner ingredients. Forty replies came back almost unanimously against, the top one at 94 points. I took the reasons apart against data. IFRA really is far stricter on baby products: 156 of 171 materials, a median of 11.6 times, and one at 130,303 times. But that category is babies, not eight-year-olds. And the reply warning that citrus hydrosols are phototoxic is wrong.
Safety · 7 2024-03-31 28 min read My database cannot settle the synthetic-versus-natural argument, because its two fields contradict each other Someone fed up with "non-toxic" marketing started a thread that ran to 97 replies. It contains one claim specific enough to test: naturals will not last more than 24 hours on skin. I tested it, and the two relevant fields give opposite answers. By the natural/synthetic field, naturals average 182.7 hours against synthetics' 97.7. By the natural-occurrence field, materials not found in nature average 172.1 against 136.1. And 306 records say "not found in nature" in one field while being labelled natural in the other. That category is not clean in the data.
Sourcing · 13 2023-12-09 28 min read "Look up how many formulas it appears in before you buy" — sound advice, with three traps in it A 34-reply thread taught beginners a purchasing method: check how many formulas a material actually appears in. I ran it against 954 deduplicated public formulas and got occurrence counts and dose ranges for 2,381 materials, plus three traps that distort the ranking: one molecule under two names, naturals split across origins, and rows that are pre-dilutions. It also caught what our own starter list is missing.
Reading the data · 10 2023-11-07 22 min read Perfumers are tired of being asked how long it lasts. The number exists — it just isn't measuring what the asker means. On 1,372 rows cleaned of censored values and of tests run below full strength, the median is 76 hours and 87% reach eight or more. Those hours are recorded neat at 100%, and they describe a material on a strip. Someone asking how long a perfume lasts wants its behaviour on skin, which is a different number.
Reading the data · 12 2023-11-27 21 min read The pyramid says 28 notes. The brand says 6. How many materials are actually in there? A beginner counted the notes on a fragrance page and asked whether all of them were really dosed. Fifty-four replies split into two camps and nobody opened the source. I checked the brand's own copy, then parsed 954 deduplicated public demo formulas: median 17 materials, but a median of 10 carries 90% of the weight. The longer the list, the longer the sub-1% tail.
Reading the data · 13 2024-03-23 33 min read Checking an AI's answer about a material: I took the forum's own "good example" and matched it line by line against the database Someone asked a chatbot what alpha carrot ionone butter smells like. The material does not exist; it described it anyway. The thread ran to 130 replies. One user posted their own output as a demonstration of correct use, so I checked its three figures against a 42,225-material database: one close, one with no matching record, and one that contradicts the source description outright — the AI said rooty and damp rather than sweet, and cold, where the database says sweet and warm and mentions white chocolate. This site's articles are written by an AI, so the checking procedure is laid out here in full.
Reading the data · 14 2024-04-16 29 min read Can jamming GC-MS protect a formula? I measured how formula weight is distributed Someone posted an anti-dupe technology: a colourless, odourless base added to a fragrance to interfere with GC-MS, which across 133 tested ingredients caused 93 to be incorrectly quantified and 25 incorrectly identified. A GC analyst who reverse-engineers fragrances at a Givaudan-owned company replied that they are only expected to get 70 to 90% of the way, with the perfumer's nose doing the rest. I measured how big that rest is across 953 formulas: the top three materials carry 54.7% of the weight, and knowing only the 344 most common materials covers 83% of a median formula's weight.
How to read this data · 11 2023-11-11 21 min read That "400 hours" for Ambroxan is where its test stopped, not how long it lasted The raw field reads "> 400 hour(s) at 10.00 % in dipropylene glycol" — a lower bound, a tenth of full strength, in a solvent. The numeric column keeps none of that, just 400.0. I ranked it against neat materials three times before noticing. My second mistake was assuming the error had a direction.
Smell science · 3 2023-10-26 9 min read Synthetic musks are not one family: structures, smell blindness and environmental fate Nitro, polycyclic and macrocyclic musks differ in structure, regulation and environmental behaviour, while receptor genetics changes how strongly people smell them.
Smell science · 4 2023-10-30 9 min read What plants, yeast and bees do with the same aroma molecules Leaf alcohol is a wound signal, isoamyl acetate is both a yeast product and a bee alarm, and methyl anthranilate links grape aroma with plant defence.
Smell science · 5 2023-11-03 8 min read Why smell research keeps using the same odorants: controls, receptors and genes Phenethyl alcohol supplies a floral control, fatty aldehydes helped establish receptor selectivity, and beta-ionone connects receptor genetics to perception.
Sourcing · 8 2023-09-20 15 min read Half the perfumery palette is declared for food use as well 64.8% of 4,620 accessible materials carry a FEMA, JECFA, CoE or FLAVIS number, and coverage tracks declared use almost exactly: 90% of flavouring agents, 3% of fragrance-only ones. The exception worth knowing is coumarin, which neither the US nor the EU authorises as an added flavouring.
Sourcing · 9 2023-09-24 15 min read 1,560 materials have a boiling point and no longevity figure. Does the boiling point substitute? On 770 rows cleaned of censored values and estimated boiling points, median substantivity runs 8, 16, 44, 124, 252 hours across quintiles — monotonic, about thirtyfold, Spearman 0.62. It ranks. It does not predict: the lowest band also contains something lasting 400 hours.
Sourcing · 10 2023-09-28 11 min read When yeast makes fragrance: patchoulol, peach lactone and Ambrox Fermentation and biocatalysis can make the same fragrance molecule by a different route. Patchoulol, gamma-decalactone and Ambrox show what changes.
Sourcing · 11 2023-10-02 10 min read Why fragrance-material names mislead: trade names, plants, nicknames and CAS Hedione can disappear from a catalogue, cedarwood may not be cedar, and aldehyde C-14 is not an aldehyde. A practical guide to material names.
Sourcing · 12 2023-10-22 8 min read Natural fragrance materials are not guaranteed: sandalwood, frankincense and tonka Sandalwood oil output has contracted, frankincense habitat may retreat, and tonka still begins with a gathering economy. Supply starts before the price list.
Safety · 1 2023-10-14 7 min read Why citrus oils can be phototoxic: the problem is not simply ‘bergamot’ Bergamot phototoxicity requires furocoumarins and ultraviolet exposure. Whole, bergapten-reduced and batch-variable oils are not interchangeable.
Safety · 2 2023-10-18 10 min read How to read fragrance-safety studies: hazard, exposure and weight of evidence Coumarin, Cashmeran, Iso E Super and vetiver show why species, dose, model and evidence weight must be read separately.
Smell science · 1 2023-10-06 10 min read Why spices feel cold, hot or warm: menthol, cinnamaldehyde and eugenol Menthol cools, cinnamaldehyde burns and eugenol feels warm because they activate different TRP channels in the mouth, nose and skin.
Smell science · 2 2023-10-10 11 min read Does a scent relax, heal wounds or change behaviour? How to read the evidence Cedrol, Hedione, sandalwood odorants and myrrh all have striking studies. Four questions keep the headline inside the evidence.
Starting out 2023-09-07 11 min read The fragrance wheel you know was built to sell perfume, not to buy materials The familiar wheel answers 'which perfume is like the one I liked'. If you are buying raw materials you are asking something else: 'what do I buy to make this smell'. Two different questions, and only one of them has a wheel most people have seen.
Starting out · 1 2023-01-09 13 min read Your first ten materials: buy these, not a starter kit Most beginner kits give you thirty 2ml vials. You run out before you understand anything. Here are ten materials that will last a whole learning phase, why these ten, and what to practise with each.
Starting out · 2 2023-01-13 11 min read It isn't your nose: dilution is the first real skill Beginners smell everything neat, decide it's all harsh and indistinguishable, and conclude they have no talent. The problem is concentration, not ability. Why to dilute, to what, and a repeatable routine with minimal kit.
Starting out · 3 2023-01-17 14 min read Why 0.1% drowns out 30%: threshold decides who speaks in a formula The same single drop disappears in one material and dominates the bottle in another. The difference isn't how much you used — it's odour threshold. Using the 802 materials in our data that carry a recommended evaluation strength.
Starting out · 4 2023-09-11 22 min read Reading a raw material datasheet: what each number changes about your decision Molecular weight, boiling point, flash point, specific gravity, logP. Most guides tell you what these fields are. This one tells you which decision each one changes — with the distribution across 42,225 materials, so you know what a normal value looks like. Includes the unit trap that will make you misread flash point by 100 °C.
Starting out · 5 2023-09-15 11 min read The database has 42,225 entries. Your actual palette is about three thousand. Browsing a materials database feels like unlimited choice. It is not. Of 42,225 entries here, 6,913 have a described smell, 4,462 of those have three or more suppliers, and 134 odour families collapse into ten that cover two thirds of everything. What that means for someone deciding what to buy.

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