Skip to content

Hair Dye

2,4-DIAMINOPHENOL

CAS 95-86-3
30

Safety score · 0–100

Caution

Derived from EU CosIng regulatory status, PubChem hazard data and published research. How we score.

About

A reactive aromatic diamine hair-dye intermediate. The free base form is broadly restricted in EU cosmetics — only its dihydrochloride salt is permitted at capped concentrations.

2,4-Diaminophenol (CAS 95-86-3) is an oxidative hair-dye precursor in the aromatic aminophenol family. The SCCS has issued a dedicated opinion (SCCS/1635/22 and predecessors) concluding that 2,4-diaminophenol itself is not safe; only the dihydrochloride salt (CAS 137-09-7) is listed in EU cosmetics Annex III with a 2.0% on-head maximum and detailed labeling requirements. It is a strong skin sensitizer, can induce methemoglobinemia, and has acute toxicity classifications under GHS. Used outside its permitted salt form and concentration window, it presents serious safety concerns.

Function

HAIR DYEING

Skin benefits

  • No safe cosmetic use outside the restricted salt form

Known concerns

  • Free base is not permitted in EU cosmetics
  • Strong skin sensitizer
  • Methemoglobinemia risk
  • Acute toxicity

References

EU

EU CosIng database

European Commission cosmetic ingredient registry — regulatory status, restrictions, authorised functions.

Related hair dyes

30
2-[(3-Aminopyrazolo[1,5-a]pyridin-2- yl)oxy]ethanol hydrochloride
Hair Dye
 30
3,4-Diaminobenzoic acid, when used as a substance in hair dye products
Hair Dye
 30
HYDROXYPROPYL BIS(N-HYDROXYETHYL-P-PHENYLENEDIAMINE) HCL
Hair Dye
 32
2,4-DIAMINO-5-METHYLPHENOXYETHANOL
Hair Dye
 32
2-METHYL-5-HYDROXYETHYLAMINOPHENOL
Hair Dye
 28
HYDROXYPROPYL-P-PHENYLENEDIAMINE HCL
Hair Dye
 32
RESORCINOL
Hair Dye
 35
4,6-BIS-(2-HYDROXYETHOXY)-M-PHENYLENEDIAMINE HCL
Hair Dye

Check your shelf

Find 2,4-DIAMINOPHENOL in your products.

Scan any cosmetic product with LuxSense to see if it contains 2,4-DIAMINOPHENOL and get a full ingredient breakdown with safety scores.

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.