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fragrance component

Hydroxycitronellal

Synthetic fragrance ingredient contributing sweet, soft, floral/muguet (lily of the valley) notes to fine fragrance. On the EU's 26 mandatory fragrance allergen disclosure list.

Benefits
  • Sweet, soft, muguet (lily of the valley) fragrance character
  • Used in floral and aldehydic fragrance compositions
  • Soft, powdery base note modifier
  • Mid-to-low volatility fixative function
  • Used in both prestige and mass fragrance
Example uses
  • Fine fragrance
  • Floral body lotions
  • Eau de toilette
  • Fragrance-preserved haircare
  • Skin-scented serums
Mechanism of action
Functions via direct olfactory receptor binding from its aldehyde-alcohol molecular structure. No pharmacological skin mechanism. The aldehyde group is the principal sensitising moiety — it can react with skin proteins forming hapten-protein complexes that trigger type IV hypersensitivity reactions in sensitised individuals.
Clinical evidence · Moderate

RIFM safety assessments completed. Sensitisation potential characterised as higher than many fragrance components. IFRA restrictions reflect actual sensitisation data.

Effective concentration range
q.s. (IFRA restricted in leave-on)
Formulation notes
Oil-soluble fragrance component. EU mandatory allergen disclosure required. IFRA use restrictions for leave-on applications.
Watchouts
Documented contact allergen — on EU mandatory disclosure list. Higher sensitisation rate compared to some other fragrance allergens. IFRA has issued restricted use guidelines in leave-on products.
Controversies & overclaims
Hydroxycitronellal has one of the higher sensitisation rates among EU mandatory fragrance allergens. Its continued use in prestige fragrance despite this designation reflects the fragrance industry's slow translation of allergen science to product reformulation.
Market positioning
Marketed as a floral fragrance note. Accurate for function. The sensitisation data is not typically disclosed to consumers.
Comedogenicity

0 / 5

Sensitisation risk

High

INCI & aliases

Hydroxycitronellal

2-(4-methylpentyl)-1,3-dioxolane-2-acetaldehyde (IUPAC) · 7-hydroxy-3,7-dimethyloctanal

Clean beauty perception

Scrutinised in clean-beauty fragrance transparency. Rarely disclosed at ingredient level by consumer-facing brands using complex fragrance compositions.

Related ingredients
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