Body & Beauty / Compounds / trans-2-Nonenal

trans-2-Nonenal on your skin: a safety profile

Moderate risk

(People-specific data is limited; this page draws from human adult context.) Alpha,beta-unsaturated aldehyde (enal) — reactive electrophile; potential skin sensitizer via Michael addition to skin proteins; mucosal irritant; some are natural food aroma components

What is trans-2-nonenal?

The IUPAC name is (E)-non-2-enal.

Also known as: (E)-non-2-enal, 2-NONENAL, 3-Hexylacrolein, beta-Hexylacrolein.

IUPAC name
(E)-non-2-enal
CAS number
18829-56-6
Molecular formula
C9H16O
Molecular weight
140.22 g/mol
SMILES
CCCCCCC=CC=O
PubChem CID
5283335

Risk for people

Moderate risk

Alpha,beta-unsaturated aldehyde (enal) — reactive electrophile; potential skin sensitizer via Michael addition to skin proteins; mucosal irritant; some are natural food aroma components

Regulatory consensus

1 regulatory bodyhas classified trans-2-Nonenal.

AgencyYearClassificationNotes
FDA1965GRASGRAS — naturally occurring aldehyde

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 trans-2-nonenal

  • Food — natural flavoring, fruit/vegetable aroma
  • Personal Care — fragrance
  • 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 trans-2-Nonenal:

  • Nonanal
    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×
  • Violet leaf absolute
    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 trans-2-nonenal?

trans-2-Nonenal appears in: natural flavoring (Food); fruit/vegetable aroma (Food); fragrance (Personal care); perfume (Fragrance); cologne (Fragrance).

See trans-2-Nonenal in the body app

Look up products containing trans-2-nonenal, 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 →