Fragrance allergen

Coumarin

Coumarin is a sweet-smelling crystalline compound found notably in the tonka bean. In perfumery it brings a warm, hay-like, vanilla-tinged sweetness and helps other notes last. Industry also makes it by synthesis. Under EU rules it must be named on a label once it passes set concentration limits.

Formula
C9H6O2
Molar mass
146.14 g/mol
CAS
91-64-5

Where it comes from

Coumarin occurs naturally in tonka beans, cassia and lavender oils. It is also reported in woodruff, bison grass and melilot (sweet clover). Factories make it synthetically instead. One route is the Perkin reaction, in which salicylaldehyde reacts with acetic anhydride in the presence of sodium acetate to give coumarin and acetic acid.

Smell and use

Sweet and warm, like new-mown hay with a vanilla and tonka bean edge. Arctander called it herbaceous-warm and somewhat spicy, turning more hay-like, nut-like and tobacco-like when very dilute.

Perfumers use coumarin to support herbaceous notes such as lavender, lavandin, rosemary, citrus oils and oakmoss, and as a fixative. One classic account calls it almost a standard ingredient of fougere types. Outside perfume it has been used in soaps, tobacco and rubber products, and was formerly important as a food flavour.

On the label

Named on 60% of the 6,851 perfume ingredient lists we hold (4,122 perfumes).

EU
Annex III, entry 77. Must be named above 0.001% in leave-on products (0.01% rinse-off).
Great Britain
Required, same thresholds. GB Annex III
Patch tests
In Fragrance Mix II, a standard skin-clinic panel.

Coumarin is one of the original 26 fragrance allergens the EU requires to be named on labels. The SCCS opinion SCCS/1459/11 places it in List A, the most frequently reported and well-recognised consumer allergens. Naming applies above 0.001% in leave-on and 0.01% in rinse-off products. IFRA has a Standard restricting its level by product type. In ECHA notifications aggregated by PubChem, 92.9% of those giving hazard codes include H317 (skin sensitiser).

A list that does not name it does not prove it is absent: brands only have to name it above the threshold.

Frequency by concentration

  • Eau de parfum 61% of 4,898
  • Eau de toilette 59% of 1,227
  • Extrait 53% of 341
  • Parfum 77% of 191
  • Cologne 47% of 108
  • Body spray 62% of 42
  • Other 48% of 27

Share of the perfumes we hold a list for, in each concentration.

Named alongside

Share of the lists naming Coumarin that also name each of these.

Notes whose materials include it

Perfumes whose box names it

Common questions

What does coumarin smell like?

It smells sweet and warm, like new-mown hay with a vanilla and tonka bean edge. Sources describe it as herbaceous-warm and somewhat spicy, and more hay-like or nut-like when very dilute.

Is coumarin natural or synthetic?

Both exist. It occurs naturally in tonka beans, cassia and lavender oils, and it is also made industrially, for example by the Perkin reaction from salicylaldehyde. The molecule is the same either way.

Why is coumarin on my perfume label?

EU rules treat coumarin as a fragrance allergen. It has to be named in the ingredient list, rather than sitting under Parfum, when it exceeds 0.001% in leave-on products or 0.01% in rinse-off products.