Styrene on your skin: a safety profile
Moderate risk(People-specific data is limited; this page draws from human adult context.) IARC 2A (2019 upgrade); leukemia, NHL; occupational exposure in fiberglass manufacturing.
What is styrene?
Also known as: Ethenylbenzene, Phenylethylene, Vinylbenzene, Styrol.
- IUPAC name
- styrene
- CAS number
- 100-42-5
- Molecular formula
- C8H8
- Molecular weight
- 104.15 g/mol
- SMILES
- C=CC1=CC=CC=C1
- PubChem CID
- 7501
Risk for people
Moderate riskIARC 2A (2019 upgrade); leukemia, NHL; occupational exposure in fiberglass manufacturing.
Regulatory consensus
17 regulatory and scientific bodies have classified Styrene. The classifications differ — that's the data.
| Agency | Year | Classification | Notes |
|---|---|---|---|
| IARC | 2019 | Group 2A (probably carcinogenic to humans) | Reclassified from 2B; leukemia, NHL; Monograph 121 |
| US EPA | 2010 | Suggestive evidence of carcinogenic potential | IRIS; lymphohematopoietic cancers; occupational and consumer exposure |
| EPA CTX / NTP RoC | — | Reasonably Anticipated to be a Human Carcinogen | |
| EPA CTX / IARC | — | Group 2A - Probably carcinogenic to humans | |
| EPA CTX / Health Canada | — | Group III: CEPA (possible germ cell mutagen, and possibly carcinogenic to humans) | |
| EPA CTX / Health Canada | — | Group III: CEPA (possible germ cell mutagen; possibly carcinogenic to humans) | |
| EPA CTX / CalEPA | — | Known human carcinogen | |
| EPA CTX / Genetox | — | Genotoxicity: positive (Ames: positive, 74 positive / 44 negative reports) | |
| EPA CTX / Genetox | — | Genotoxicity: positive (Ames: positive, 74 positive / 44 negative reports) | |
| EPA CTX / Skin-Eye | — | Eye Irritation: Eye Irrit. 2 (score: high) | |
| EPA CTX / Skin-Eye | — | Skin Irritation: Skin Irrit. 2 (score: high) | |
| EPA CTX / Skin-Eye | — | Eye Irritation: Category 2A (score: high) | |
| EPA CTX / Skin-Eye | — | Skin Irritation: Category 2 (score: high) | |
| EPA CTX / Skin-Eye | — | Eye Irritation: Eye Irrit. 2 (score: high) | |
| EPA CTX / Skin-Eye | — | Skin Irritation: Skin Irrit. 2 (score: high) | |
| EPA CTX / Skin-Eye | — | Eye Irritation: Category 6.4A (Category 2A) (score: high) | |
| EPA CTX / Skin-Eye | — | Skin Irritation: Category 6.3A (Category 2) (score: high) |
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 styrene
- Industrial Facilities — Manufacturing plants, Chemical storage areas, Waste treatment sites
- Occupational Environments — Factories, Warehouses, Transportation vehicles
-
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 Styrene:
-
Fragrance-free formulations
Trade-offs: Consumer preference for scented productsRelative cost: 1.2-2×
-
Essential oil-based fragrances (with disclosure)
Trade-offs: Natural does not mean safe — many essential oils are skin sensitizersRelative cost: 2-5×
Frequently asked questions
What products contain styrene?
Styrene appears in: Manufacturing plants (Industrial facilities); Chemical storage areas (Industrial facilities); Factories (Occupational environments); Warehouses (Occupational environments); perfume (Fragrance).
Why do regulators disagree about styrene?
Styrene has been classified by 17 agencies including IARC, US EPA, EPA CTX / NTP RoC, EPA CTX / IARC, EPA CTX / Health Canada, with differing conclusions. 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. See the regulatory consensus table on this page for the full picture.
See Styrene in the body app
Look up products containing styrene, compare to alternatives, and explore the full data record.
Open in body View raw API dataSources (2)
- IARC Monographs Volume 121: Styrene, Styrene-7,8-Oxide, and Quinoline (2019) — regulatory
- US EPA IRIS Assessment: Styrene (2010) — regulatory
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 →