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Limonene

A citrus-peel scent chemical on the EU’s list of fragrance allergens. Air turns it into a stronger allergen as it ages.

What it does

It’s a scent chemical found in citrus peel oils. Air turns it into a stronger allergen. The EU’s scientific committee lists that aged form among 12 fragrance allergens of special concern, each with over 100 reported allergy cases.

The EU’s ingredient database lists it as a fragrance (adds scent) and a solvent (dissolves other ingredients).European Commission, CosIng (© European Union, CC BY 4.0) · uses put in plain words by Drop ↗

The evidence, graded

expert consensusLinalool, limonene, geraniol, citral, eugenol, cinnamal, isoeugenol and hydroxycitronellal are among the 12 fragrance chemicals the EU's scientific committee singled out in 2012 for their number of reported allergy cases. For linalool and limonene, that is their air-oxidized form. Coumarin, cinnamyl alcohol, farnesol and HICC are in the same top group. All are on the EU's original list of 26 fragrance allergens labels must name.SCCS 2012 · European Commission SCCS ↗

expert consensusHexyl cinnamal, anise alcohol, alpha-isomethyl ionone, citronellol, coumarin, benzyl benzoate and amyl cinnamal are also on the EU's 26-name fragrance label list. The EU's scientific committee counts all seven as established contact allergens. Coumarin is in its top group, with more than 100 reported cases. Anise alcohol has 10 or fewer; the other five have 11 to 100.SCCS 2012 · European Commission SCCS ↗

Graded per the methodology: strong · moderate · emerging · expert consensus. A weak source on a strong claim gets the weaker label.

Also known as

d-limonene, citrus terpene

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