Material guide: ylang ylang oil — four different products sharing one CAS number

The previous piece cited a German study of 10,930 patients that tested twelve essential oils. The one with the highest positivity is this. Here it is in full.

And before you buy it, you hit a naming problem.

The short version

• Ylang ylang is sold as successive cuts of one distillation: extra, I, II and III. The earlier the fraction, the lighter and more floral; later fractions run heavier and woodier.
• Grades I, II, III and cananga oil all carry the same CAS in the database: 68606-83-7. This is the inverse of the Iso E Super case — that was one material spread across four CAS numbers; this is four products crammed under one.
• Recorded longevity varies by grade: generic ylang ylang oil 140 hours, grade I 319 hours.
• In Geier and colleagues' 2022 study, ylang ylang oil (I + II) had the highest positivity of twelve essential oils at 3.9%.

The basics

CAS	8006-81-3 (generic oil, absolute, CO₂ extract) / 68606-83-7 (grades I, II, III and cananga oil)
Botanical source	Flowers of Cananga odorata
Type	Natural essential oil, multi-component mixture
Odour	Floral, petal, neroli, lily, spicy (grade I additionally records jasmin, lily of the valley, balsamic, earthy, woody, winey)
Odour family	floral
Strength	Medium (evaluate at 10% or below)
Longevity	Generic oil 140 hours; grade I 319 hours; cananga oil 116 hours
Appearance	Pale yellow clear liquid
Flash point	76.67 °C (generic oil); grade I above 93 °C
Specific gravity	0.948–0.968 @ 25 °C
Refractive index	1.497–1.511 @ 20 °C
Water solubility	18.24 mg/L @ 25 °C (est)
Other solubility	Soluble in 0.5–2 volumes of 60% alcohol; non-discolouring in most media
Storage	24 months or longer; cool, dry, sealed, away from heat and light
Regulatory	FEMA 3119, CoE
Suppliers	Generic oil 93; grade III 45; grade I 42; cananga oil 40; grade II 30
Corpus rank	20th (113 of 953 formulas, 11.8%, median dose 2.00%)

A natural oil has no single formula or molecular weight. The physical values above are representative for this class of goods; batch decisions come from the supplier's COA.

One still, four cuts

Ylang ylang grades are not a quality ranking. They are cut points in the distillation.

Once a batch of flowers goes into the still, the distillate is collected in sequence. The earliest fraction is the lightest, the most floral and the most expensive, conventionally called extra; then I, II and III in order. Later fractions carry more high-boiling components and drift woody, balsamic and earthy. Everything recombined is sold as complete.

So the words "ylang ylang oil" specify nothing. The recorded longevity shows it: generic ylang ylang oil sits at 140 hours while grade I sits at 319, more than double.

Correction (2026-08-28): these two figures point the opposite way to how the trade describes the fractions. Somebody on the forum who has used all four wrote that Extra is toppier, with more floral impact and somewhat shorter longevity, while the third fraction lasts longer. Both figures are in the database under matching conditions (both neat), and the substantivity field for grades II and III is empty. I read the numbers without checking them against the trade description, and I cannot tell which side is right. See What percentage is three drops in 10 mL?. Grade I's odour field is longer too — beyond petal and neroli it records jasmin, lily of the valley, balsamic, earthy, woody and winey.

Cananga oil is a further step sideways. It also comes from Cananga odorata, usually from a different cultivar and a different origin (commonly Java), smells sweeter, greener and more animalic, and the database records 116 hours.

Four products, one CAS

This is the part to remember.

In the database, grade I, grade II, grade III and cananga oil all four carry CAS 68606-83-7. Generic ylang ylang oil, ylang ylang absolute and the CO₂ extract use a different number, 8006-81-3.

Product	CAS	Suppliers
Ylang ylang flower oil (generic)	8006-81-3	93
Ylang ylang flower oil III	68606-83-7	45
Ylang ylang flower oil I	68606-83-7	42
Cananga oil	68606-83-7	40
Ylang ylang flower oil II	68606-83-7	30
Ylang ylang flower absolute	8006-81-3	10

In the IFRA piece we covered the opposite case: the IFRA Standard for Iso E Super is filed under the systematic name OTNE and covers four CAS numbers, which is why the trade name returns nothing. That is one material scattered across several numbers.

Ylang ylang is the same problem running the other way: four commercially distinct products, smelling and pricing differently, packed under one number.

The practical consequence: when buying ylang ylang, the CAS is not enough to specify what you want. State the grade (extra / I / II / III / complete) and the origin (Madagascar, Comoros, Java) on the order. This is the naturals version of material names mislead.

It tops twelve essential oils

Geier and colleagues, in Contact Dermatitis in 2022, analysed German IVDK network data from 2010 to 2019. 10,930 dermatitis patients were patch tested in an aimed manner with twelve essential oils, and 908 (8.3%) reacted to at least one.

Ylang ylang oil (I + II) came in highest at 3.9%. Lemongrass oil followed at 2.6%, then jasmine absolute and sandalwood oil at 1.8% each.

de Groot and Schmidt's 2017 review in Dermatitis devotes a chapter to sandalwood oil, ylang ylang oil and jasmine absolute, covering botanical origin, uses, chemical composition, cases of contact allergy, and the ingredients responsible.

How to read that 3.9%. First, it describes a dermatology clinic population rather than a general prevalence, and the authors' overall conclusion is that sensitisation to essential oils occurs "albeit infrequently in most cases". Second, concomitant reactions between oils and between oils and fragrances are frequent, so a positive does not necessarily convict ylang ylang.

What it supports: of the twelve oils tested, this is the one that most warrants care — and gloves plus concentration control are the corresponding response.

Why it turns up in so many formulas

Ylang ylang ranks 20th in our corpus, appearing in 11.8% of formulas at a median dose of 2.00% — frequent but lightly dosed, the classic seasoning position.

The reason is that it is already a small formula in itself. Dozens of materials in the database record their natural occurrence in ylang ylang oil, including benzyl salicylate at 1.37%, alpha-farnesene 2.34%, alpha-humulene 0.74% and para-cresol 0.09%. Adding a little ylang ylang adds floral, balsamic, woody and a touch of animalic all at once.

In the pairing analysis it belongs to the jasmine / white floral cluster, and pairing it with benzyl acetate is the most common combination.

When you smell it

• If you buy only one, start with grade I or complete. Extra is the most expensive and the least like what most people picture as ylang ylang; III is heavy. The middle is the most useful place to begin.
• Line up two grades. Buy small bottles of I and III and smell them together if you can. It is the most direct demonstration of "same flower, cut at different times" available, and it beats any amount of reading.
• Start at 5%. At low concentration it is floral; push it up and a distinct plastic and winey quality appears. Plenty of people dislike their first encounter with the neat oil.
• Expect the winey note. Grade I's odour field records it explicitly. That is not spoilage; that is the material.

Buying and storage

Specify three things on the order: grade, origin, and whether a COA comes with it. Writing only "ylang ylang oil" gets you whatever that supplier defaults to.

Generic ylang ylang oil has a flash point of 76.67 °C, lower than most essential oils, so mind transport and storage; grade I sits above 93 °C. Shelf life is 24 months or longer, sealed and dark.

It contains components that oxidise, so run the decant, date, keep a reference routine. An ageing natural oil drifts upward in sensitising potential, the mechanism covered in the previous piece.

Regulatory and safety

Four GHS statements: H302 harmful if swallowed, H315 causes skin irritation, H317 may cause an allergic skin reaction, H320 causes eye irritation.

Acute toxicity is generous: oral rat LD50 above 5,000 mg/kg, dermal rabbit LD50 above 5,000 mg/kg. Which restates that acute toxicity and sensitisation are separate questions — the LD50 looks excellent while the patch test positivity is the highest of the twelve.

Register listings are FEMA 3119 and CoE. IFRA carries a Standard for ylang ylang oil; check the current version for use limits — here is how to check that yourself.

→ Ylang ylang oil in the database: full physical data, 93 suppliers and suggested blends. → Search by odour: try "ylang floral spicy".

References

J. Geier et al., Contact sensitization to essential oils: IVDK data of the years 2010-2019, Contact Dermatitis, 87(1), 71–80 (2022). PMID 35417610. doi:10.1111/cod.14126

A. C. de Groot, E. Schmidt, Essential Oils, Part VI: Sandalwood Oil, Ylang-Ylang Oil, and Jasmine Absolute, Dermatitis, 28(1), 14–21 (2017). PMID 28002230. doi:10.1097/DER.0000000000000241