Hair Dye
PYROCATECHOL
Safety score · 0–100
Avoid
Derived from EU CosIng regulatory status, PubChem hazard data and published research. How we score.
About
A dihydroxybenzene (catechol) historically used as a hair-dye intermediate. Now prohibited in cosmetics in the EU — do not use.
Pyrocatechol (1,2-dihydroxybenzene, CAS 120-80-9), also called catechol, is a phenolic compound historically used as an oxidation hair-dye intermediate. Following SCCS review, the EU added pyrocatechol to the Annex II list of substances prohibited in cosmetic products. It is acutely toxic by ingestion, corrosive and strongly sensitizing on skin contact, and has caused methemoglobinemia in humans at sufficient exposures. GHS classifications include acute toxicity, skin corrosion/irritation, and sensitization. There is no safe cosmetic use case given available alternatives.
Function
Skin benefits
- No cosmetic-safe use case
Known concerns
- EU-prohibited (Annex II) in cosmetics
- Acutely toxic and corrosive
- Strong skin sensitizer
- Methemoglobinemia risk
References
EU CosIng database
European Commission cosmetic ingredient registry — regulatory status, restrictions, authorised functions.
Related hair dyes
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This profile is for educational purposes and does not constitute medical advice. Regulatory status and scientific understanding evolve — always read the physical product label and consult a healthcare professional for personal concerns.