Material guide · 81
Material guide: lavender oil — fougère at 7.3× baseline, and it almost never shares a formula with lavandin
· 22 min read
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.
Short version: it is half of the fougère; coumarin is the other half. When you buy it, know which lavender you are buying, because at least three things go by this name and formulas do not treat them as interchangeable.
The fields
| Field | Lavender oil | Lavandin oil |
|---|---|---|
| CAS | 8000-28-0 | 8022-18-2 |
| Plant | Lavandula angustifolia | Lavandula hybrida (angustifolia × spike lavender) |
| Odour type | Floral | Floral |
| Odour | Herbal, floral, spicy, aromatic, camphoreous, balsamic, eucalyptus, woody | Floral, herbal, lavender, camphoreous, soapy |
| Strength | Medium | Medium |
| Substantivity | 12 hours | 216 hours |
| Shelf life | 24 months | 12 months |
| Boiling point | 204 °C | 211 °C |
| Specific gravity | 0.875–0.888 | 0.889–0.910 |
| Optical rotation | −3 to −10 | −2 to −5 |
| Suppliers | 99 | 51 |
| Regulatory | FEMA GRAS 2622 | FEMA GRAS 2618 |
| GHS | Combustible liquid H227 | Not listed |
Ninety-nine suppliers puts it among the most widely stocked naturals this series has covered. It is neither rare nor expensive.
That 12 hours against 216 hours
Deal with this field first, because it looks wrong on sight.
The same database gives lavender oil 12 hours of substantivity and lavandin oil 216. Eighteen times.
I cannot account for the gap. Lavandin carries more camphor and borneol, and its specific gravity and boiling point are both slightly higher, so "somewhat longer" would make sense. Eighteenfold does not. This series has met three kinds of database problem: wrong (oakmoss's natural occurrence field), incomplete (dihydro-β-ionone missing osmanthus), and mutually inconsistent but possibly all correct (octyl acetate). This field most likely belongs to the first, but I have no evidence, so here is the plain statement: do not compare these two numbers. At least one of them was measured under different conditions than the other.
In practice neither is a long material. Their place in a formula is top to middle, not base.
What it does in the corpus
It appears in 55 of 954 formulas (5.8%).
| Lavender oil | Lavandin oil | |
|---|---|---|
| Formulas | 55 | 39 |
| Median share | 6.06% | 5.56% |
| Interquartile | 3.00%–15.00% | 2.04%–14.00% |
| Maximum | 86.0% | 61.9% |
Neither is used in small amounts; both sit at a median of 5 to 6%. That is the load-bearing tier, the same band as hexyl salicylate (7.05%) from the last entry in this series.
And the number worth stopping on: of 954 formulas, exactly one uses both lavender oil and lavandin oil.
They appear in 55 and 39 formulas respectively. If they were independently distributed, chance alone would put about two formulas in the overlap. There is one. They are substitutes, not companions — a perfumer picks one and does not then add the other.
Genre: fougère at 7.3×
752 of the 954 formulas can be labelled by genre from their titles. Against that baseline:
| Genre | Of the 55 with lavender oil | Corpus baseline | Ratio |
|---|---|---|---|
| Fougère | 29% | 4% | 7.3× |
| Citrus | 24% | 14% | 1.7× |
| Green | 15% | 10% | 1.5× |
| Oriental amber | 11% | 4% | 2.8× |
| Spicy | 11% | 3% | 3.7× |
7.3× is the strongest genre concentration this series has measured. Eighty-one materials in, nothing else ties itself to a single genre the way lavender oil does.
The companion list finishes the explanation:
| Appears with | Formulas | Of its 55 |
|---|---|---|
| Coumarin | 30 | 55% |
| Bergamot oil, bergaptene reduced | 19 | 35% |
| Linalool | 18 | 33% |
| Linalyl acetate | 16 | 29% |
| Patchouli oil | 16 | 29% |
| Geranium oil bourbon | 15 | 27% |
| Benzyl acetate | 14 | 25% |
| Eugenol | 14 | 25% |
Lavender plus coumarin plus oakmoss is the definition of the fougère. More than half the lavender formulas contain coumarin, which is a high co-occurrence rate among the pairings this series has measured.
Linalool and linalyl acetate placing third and fourth is also interesting: those two are lavender oil's own principal constituents. Perfumers put in the oil and then add those two separately — using single chemicals to correct the proportions of the natural.
Lavandin's genre spread runs differently: citrus 28%, green 23%, fougère 21%, and floral only 18% against a 36% baseline. It leans clean and soapy rather than floral.
Three different things share this name
The easiest trap when buying lavender oil is that the "lavender" on the shelf is not one plant.
| Name | Species | Database record |
|---|---|---|
| Lavender oil (true lavender) | L. angustifolia | #21975, 99 suppliers |
| Lavender oil france | L. angustifolia, French | #21974, 55 suppliers |
| Lavandin oil | L. hybrida | #21881, 51 suppliers |
Lavandin is a hybrid of true lavender and spike lavender. The database note is clear about its history: "The story of Lavandin Oil is one of tremendous success. Unknown until the late 1920's, this essential oil today ranges among the world's 10 largest perfume oils from nature."
It is cheap, high-yielding and more camphoreous. It is not inferior lavender; it is a different thing, and that single-overlap figure in the corpus is the practical proof.
And the same species can vary enormously
In 2021, Liao's group harvested from the same lavandin planting on the Yun-Gui Plateau in four seasons, distilled each, and analysed by GC-MS. Yields ran 2.0% to 3.8%, highest in summer. The composition ranges:
| Constituent | Range |
|---|---|
| Total oxygenated monoterpenes | 55.4% – 81.4% |
| Eucalyptol | 38.7% – 49.8% |
| Camphor | 8.41% – 14.26% |
| α-bisabolol | 6.6% – 25.5% |
| Linalool | 4.6% – 12.5% |
Eucalyptol at 40 to 50%, linalool under 10%. That oil leans towards eucalyptus, not Provence.
Read this row carefully: it concerns one origin and one cultivar and does not generalise to all lavender oil. What it establishes is that the words "lavender oil" do not constrain what is in the oil — seasonal variation within one field is enough to move its genre.
The database's odour field has this built in. Lavender oil's odour includes camphoreous and eucalyptus, two words nobody uses when describing the lavender in a perfume, and both genuinely present in the oil.
The problem after it oxidises
In 2016, Hagvall and Christensson published a patch test study in Acta Dermato-Venereologica.
Lavender oil's two main components, linalool and linalyl acetate, autoxidise on contact with oxygen in the air, forming sensitising hydroperoxides. The group consecutively patch-tested patients with suspected allergic contact dermatitis against three things: oxidised lavender oil 6% pet., oxidised linalyl acetate 6% pet., and oxidised linalool 6% pet.
The result has two layers:
- Positive reactions to oxidised lavender oil were found in 2.8% of patients. The paper notes that oxidised lavender oil showed among the highest frequencies of contact allergy of the essential oils studied.
- Among those positives, only 56% reacted to oxidised linalool and/or oxidised linalyl acetate, while 52% reacted to the fragrance markers of the baseline series.
The second point is the paper's argument, and what its title says: patch testing with the main sensitizers does not detect all cases. In other words, what this oil produces on oxidation is not limited to the oxidation products of its two main constituents.
The practical implication is simple, and the database field already carries it: 24 months shelf life, store in a cool dry place in tightly sealed containers, protected from heat and light. That is not a tidiness instruction; oxidation changes its sensitising behaviour. An old bottle opened many times is not the same material as a new one.
Whether to buy it
- Ninety-nine suppliers. Neither price nor availability is an obstacle. Worth noting that the one that won on that anxiety scale is the capsule version, not the smelled one.
- If you want to make a fougère, you cannot skip it. 7.3× is not a coincidence, and paired with coumarin it is the skeleton of the genre.
- Buy by species name. Whether you want L. angustifolia or L. hybrida decides how camphoreous it is, and the corpus says perfumers do not mix them.
- Buy small bottles and write the opening date on them. It oxidises, and its sensitising behaviour after oxidation cannot be predicted from data on its main constituents.
What this doesn't establish
- I have not explained the 12 versus 216 hour gap. Neither measurement's conditions appear in the record, so all I can do is flag them as not comparable.
- Liao's study is lavandin on the Yun-Gui Plateau, not French L. angustifolia. The composition ranges cannot be transferred to commercial Provençal lavender oil.
- Hagvall's group tested outpatients with suspected allergic contact dermatitis, not the general population. 2.8% is a rate within that group, not a general allergy rate.
- Fifty-five and thirty-nine are both small samples. The 7.3× fougère figure rests on 16 formulas and would carry a wide interval. I did not compute one.
- "Only one formula uses both" is an observation, not an experiment. It could also reflect sourcing bias in published formulas, since multiple formulas by one author will share that author's habits.
- Doses are weight shares within the formula, not concentrations in a finished product. Comparing to IFRA limits requires multiplying by the fragrance load first.