Body & Beauty / Compounds / 2-Methylundecanal

2-Methylundecanal 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 2-methylundecanal?

Also known as: UNDECANAL, 2-METHYL-, Aldehyde M.N.A., Methylnonylacetaldehyde, Aldehyde C-12.

IUPAC name
2-methylundecanal
CAS number
110-41-8
Molecular formula
C12H24O
Molecular weight
184.32 g/mol
SMILES
CCCCCCCCCC(C)C=O
PubChem CID
61031

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

1 regulatory bodyhas classified 2-Methylundecanal.

AgencyYearClassificationNotes
IFRA2024restrictionIFRA 51st Amendment — concentration limits

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 2-methylundecanal

  • 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 2-Methylundecanal:

  • Undecanal
    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×
  • Triplal
    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 2-methylundecanal?

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

See 2-Methylundecanal in the body app

Look up products containing 2-methylundecanal, 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 →