The ingredient, explained
Coumarin
Coumarin has published research relevant to the stated experimental context.
Ingredient guide
What it is and what it does
Coumarin; 2H-1-Benzopyran-2-one
About this ingredient: EU CosIng ingredient registry (via Open Beauty Facts taxonomy) ↗
- Perfuming
- A formulation role for perfume and aromatic raw materials that give a product its scent.
Function definitions: Danish Environmental Protection Agency: Cosmetic fragrance functions ↗
Registry functions describe possible formulation roles, not results for a finished product. A dictionary entry is not an approval or a safety assessment.
A closer look
What the research shows
Human contact allergy research
Coumarin reactions occurred in 2.7% of the 367 fragrance mix II-positive patients who received the complete constituent breakdown.
What this does not tell us
This selected patch-test population does not estimate allergy prevalence in ordinary cosmetic users or show skin benefits.
Sources for this summary. PubMed 20946454 ↗
Research review checked Oct 1, 2026
Selective exact-identity review of 2 supplied local candidates and the targeted primary-source search recorded below. Bounded review, not a systematic search.
Ingredient research is not proof that a product containing this ingredient works.
Read the 1 selected study
Human contact allergy research · n=35633
Patch testing with fragrance mix II: results of the IVDK 2005-2008. ↗
Contact dermatitis · 2010
Follow the formula
Products containing this ingredient
From the wider catalogue. Linked by the ingredient list, without an efficacy ranking.
Names and identifiers
Registry identity
Coumarin; 2H-1-Benzopyran-2-one
- INCI name on ingredient lists
- COUMARIN
- CAS registry number
- 91-64-5
- EC number
- 202-086-7
Sources for this ingredient record
- EU CosIng ingredient registry (via Open Beauty Facts taxonomy) ↗ · ODbL 1.0 (Open Beauty Facts database) · Recorded Aug 8, 2026