Body & Beauty / Compounds / Allyl isothiocyanate

Allyl isothiocyanate on your skin: a safety profile

High risk

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Direct skin contact with concentrated allyl-isothiocyanate produces severe dermal sensitization + irritation per IARC vol 73 + IFRA 51st Amendment + NIOSH framework. Mustard-paste-applicator + research-laboratory + flavor-and-fragrance-manufacturing + military-CN-tear-gas-analog historical cohort all ground the high-magnitude dermal hazard envelope.

What is allyl isothiocyanate?

The IUPAC name is 3-isothiocyanatoprop-1-ene.

Also known as: 3-isothiocyanatoprop-1-ene, AITC, Redskin, Allylsenfoel.

IUPAC name
3-isothiocyanatoprop-1-ene
CAS number
57-06-7
Molecular formula
C4H5NS
Molecular weight
99.16 g/mol
SMILES
C=CCN=C=S
PubChem CID
5971

Risk for people

High risk

Direct skin contact with concentrated allyl-isothiocyanate produces severe dermal sensitization + irritation per IARC vol 73 + IFRA 51st Amendment + NIOSH framework. Mustard-paste-applicator + research-laboratory + flavor-and-fragrance-manufacturing + military-CN-tear-gas-analog historical cohort all ground the high-magnitude dermal hazard envelope.

Regulatory consensus

1 regulatory bodyhas classified Allyl isothiocyanate.

AgencyYearClassificationNotes
US FDA—Regulated under food safety frameworks (FDA GRAS, EU food additive regulations)

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 allyl isothiocyanate

  • Food — mustard, horseradish, wasabi
  • Consumer Products — insect repellent (historical)
  • 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 Allyl isothiocyanate:

  • Natural preservatives; Clean-label ingredients; Minimally processed food
    Trade-offs: Consumer label appeal ('clean label'); variable efficacy depending on food matrix and target pathogen; may alter flavor/color; regulatory status varies by jurisdiction; often more expensive per unit of preservation effect.
    Relative cost: 2-5× conventional

Frequently asked questions

Is allyl isothiocyanate safe for you?

Direct skin contact with concentrated allyl-isothiocyanate produces severe dermal sensitization + irritation per IARC vol 73 + IFRA 51st Amendment + NIOSH framework. Mustard-paste-applicator + research-laboratory + flavor-and-fragrance-manufacturing + military-CN-tear-gas-analog historical cohort all ground the high-magnitude dermal hazard envelope.

What products contain allyl isothiocyanate?

Allyl isothiocyanate appears in: mustard (Food); horseradish (Food); insect repellent (historical) (Consumer products); perfume (Fragrance); cologne (Fragrance).

See Allyl isothiocyanate in the body app

Look up products containing allyl isothiocyanate, compare to alternatives, and explore the full data record.

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Sources (6)
  1. PubChem Compound Database (2026) — database
  2. FDA 21 CFR 184.1409 + 21 CFR 582.10 — Allyl isothiocyanate generally recognized as safe (GRAS) for use as flavoring agent (mustard-essential-oil principal component; volatile + lacrimator) (2018) — regulatory
  3. IARC Monographs Volume 73 — Allyl Isothiocyanate (Group 3 Not classifiable as to its carcinogenicity to humans; sensitization + lacrimator framework) (1999) — regulatory
  4. IFRA Standard 51st Amendment — Allyl isothiocyanate concentration limits in finished fragrance products (sensitization + acute-irritation framework; finished-product 0.001-0.1% by category) (2024) — regulatory
  5. NIOSH Pocket Guide to Chemical Hazards — Allyl Isothiocyanate (CAS 57-06-7; PEL 0.4 mg/m³ + 4 mg/m³ STEL; lacrimator) (2019) — regulatory
  6. EFSA Scientific Opinion on Glucosinolates as Undesirable Substances in Animal Feed — sinigrin + allyl isothiocyanate hydrolysis-product framework + Brassica feed-quality limits (2008) — regulatory

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