Body & Beauty / Compounds / Phenylacetaldehyde

Phenylacetaldehyde on your skin: a safety profile

Moderate risk

(People-specific data is limited; this page draws from human adult context.) Fragrance aldehyde — skin sensitizer class; EU requires disclosure for select members; sensitization potency varies by structure; oxidation on shelf increases allergenicity

What is phenylacetaldehyde?

The IUPAC name is 2-phenylacetaldehyde.

Also known as: 2-phenylacetaldehyde, Benzeneacetaldehyde, alpha-Tolualdehyde, Phenylethanal.

IUPAC name
2-phenylacetaldehyde
CAS number
122-78-1
Molecular formula
C8H8O
Molecular weight
120.15 g/mol
SMILES
C1=CC=C(C=C1)CC=O
PubChem CID
998

Risk for people

Moderate risk

Fragrance aldehyde — skin sensitizer class; EU requires disclosure for select members; sensitization potency varies by structure; oxidation on shelf increases allergenicity

Regulatory consensus

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

AgencyYearClassificationNotes
IFRA2024restrictionIFRA 51st Amendment — sensitization limits
FDA1965GRASGRAS food flavoring

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 phenylacetaldehyde

  • 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 Phenylacetaldehyde:

  • Phenylethyl alcohol (PEA)
    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×
  • 2-Phenylpropionaldehyde
    Trade-offs: Removes 95-99% of dissolved contaminants including metals, PFAS, nitrates; wastes 2-4 gallons per gallon produced (improving with newer systems); removes beneficial minerals; $0.05-0.25/gallon; requires pre-treatment for longevity.
    Relative cost: 1.2-2×

Frequently asked questions

What products contain phenylacetaldehyde?

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

See Phenylacetaldehyde in the body app

Look up products containing phenylacetaldehyde, 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 →