Body & Beauty / Compounds / alpha-Hexylcinnamaldehyde

alpha-Hexylcinnamaldehyde on your skin: a safety profile

Elevated risk

(People-specific data is limited; this page draws from human adult context.) EU designated allergen (Annex III); strong skin sensitizer; IFRA restricted; cross-reacts with cinnamaldehyde; among the most common fragrance contact allergens

What is alpha-hexylcinnamaldehyde?

The IUPAC name is (2E)-2-benzylideneoctanal.

Also known as: (2E)-2-benzylideneoctanal, 2-Benzylideneoctanal, alpha-Hexylcinnamic aldehyde, alpha-Hexylcinnamyl aldehyde.

IUPAC name
(2E)-2-benzylideneoctanal
CAS number
101-86-0
Molecular formula
C15H20O
Molecular weight
216.32 g/mol
SMILES
CCCCCCC(=CC1=CC=CC=C1)C=O
PubChem CID
1550884

Risk for people

Elevated risk

EU designated allergen (Annex III); strong skin sensitizer; IFRA restricted; cross-reacts with cinnamaldehyde; among the most common fragrance contact allergens

Regulatory consensus

2 regulatory and scientific bodies have classified alpha-Hexylcinnamaldehyde. The classifications differ — that's the data.

AgencyYearClassificationNotes
IFRA2020restrictionIFRA restriction — sensitization concentration limits
EU_COSMETICS2009allergen_disclosureEU Annex III original 26 allergens

Regulators apply different standards of evidence — animal-data weighting, exposure-pattern assumptions, epidemiological power thresholds — which is why two scientific bodies can review the same data and reach different conclusions. The disagreement is the data.

Where you encounter alpha-hexylcinnamaldehyde

  • Personal Care — perfume, soap, shampoo, cosmetics
  • Consumer Products — cleaning products, candles, air fresheners
  • Fragrance — perfume, cologne, scented personal care products, household fragrance products, candles
    Identified in Fragrance Ingredient Safety Priority Research database (2,325 ingredients)

Safer alternatives

Lower-risk approaches that achieve a similar outcome to alpha-Hexylcinnamaldehyde:

  • alpha-Amylcinnamaldehyde
    Trade-offs: Alternative fragrance ingredient; individual safety profile should be assessed per IFRA standards; sensitization potential varies by compound; patch testing recommended for sensitive individuals.
    Relative cost: 1.2-2×
  • Floral aldehydes
    Trade-offs: Alternative fragrance ingredient; individual safety profile should be assessed per IFRA standards; sensitization potential varies by compound; patch testing recommended for sensitive individuals.
    Relative cost: 1.2-2×

Frequently asked questions

What products contain alpha-hexylcinnamaldehyde?

alpha-Hexylcinnamaldehyde appears in: perfume (Personal care); soap (Personal care); cleaning products (Consumer products); candles (Consumer products); perfume (Fragrance).

See alpha-Hexylcinnamaldehyde in the body app

Look up products containing alpha-hexylcinnamaldehyde, compare to alternatives, and explore the full data record.

Open in body View raw API data

Sources (1)
  1. PubChem Compound Database (2026) — database

Reference data, not professional advice. Aggregates publicly available regulatory and scientific data; not a substitute for veterinary, medical, legal, or regulatory advice. Why we built ALETHEIA →