Linalool
Also known as Linalool, Linalol, 3,7-Dimethyl-1,6-octadien-3-ol, 2,6-Dimethyl-2,7-octadien-6-ol
“EU CosIng says: restricted.”
Linalool is a naturally-occurring monoterpene tertiary alcohol used widely as a fragrance ingredient in cosmetic and personal care products. Pure linalool is a prehapten with low intrinsic sensitization potential; the major skin allergens are linalool hydroperoxides formed via autoxidation on air exposure (Sköld 2002 identified the primary hydroperoxide 7-hydroperoxy-3,7-dimethyl-octa-1,5-diene-3-ol). Large consecutive patch-test studies confirm clinically significant sensitization rates: the German IVDK 2018-2020 study (Schubert 2023, n=5,511) reported 8.8% positive reactions to linalool hydroperoxides at diagnostic concentration. Wilkinson et al. (2017) recommended Lin-OOHs at 1.0% in the British baseline patch test series. CIR has NOT issued a published safety assessment for linalool — the ingredient is absent from both the December 2017/July 2018 QRT and the September 2022 QRT (verified by alphabetical traversal). Under EU Regulation 1223/2009, linalool is listed in Annex III (Entry 84) as a regulated fragrance allergen requiring label declaration when present above 0.001% in leave-on products or 0.01% in rinse-off products. SCCS/1459/11 (2012) discusses linalool as part of a class-level fragrance allergen review but did not issue a standalone ingredient-specific opinion.
Naturally occurring in many essential oils (lavender, bergamot, rosewood, coriander) — provides characteristic fresh, floral fragrance notes used widely in perfumery and personal care
Pure (unoxidized) linalool itself shows no sensitization in guinea pig studies (Sköld 2002) — proper formulation with antioxidants and appropriate packaging can substantially reduce real-world allergenicity
Well-characterized chemistry and oxidation pathway (Sköld 2002, multiple follow-up studies) — formulators have actionable guidance for minimizing hydroperoxide formation
- · Regulated EU fragrance allergen (Annex III Entry 84): label declaration required above 0.001% (leave-on) or 0.01% (rinse-off) due to sensitization potential in susceptible individuals
- · SCCS/1459/11 (2012) covers linalool only as part of a multi-ingredient fragrance allergen class review, not as a standalone ingredient-specific safety opinion
Linalool hydroperoxides (autoxidation byproducts) are the major sensitizers, not pure linalool itself — formulation age, packaging, and antioxidant content all materially affect real-world allergenicity
IVDK 2018-2020 patch testing of 5,511 consecutive patients showed 8.8% positive reactions to linalool hydroperoxides (Schubert 2023) — one of the highest sensitization rates among the 26 EU mandatory-disclosure fragrance allergens
No published CIR safety assessment as of September 2022 QRT; absence from CIR is a notable evidence gap relative to other fragrance allergens (limonene also has no CIR assessment; benzyl salicylate, eugenol, geraniol all have CIR assessments)
EU Regulation 1223/2009 Annex III (Restricted Substances) — Entry 84: Linalool, CAS 78-70-6 (EC 201-134-4); fragrance allergen labeling r…
“Entry 84, Linalool, CAS 78-70-6 (EC 201-134-4); the presence of the substance must be indicated in the list of ingredients referred to in Article 19(1)(g) when its concentration exceeds: 0,001 % in leave-on products, 0,01 % in rinse-off products”— EU Reg 1223/2009 Annex III, Entry 84