2-Chloro-p-Phenylenediamine
AKA “4-diaminobenzene, 4-Benzenediamine, 4-phenylenediamine, Ursol Brown O, 3-Chloro-4-aminoaniline, 4-Diamino-2-chlorobenzene, 4-benzenediamine, o-Chloro-p-phenylenediamine”
Synthetic
Ingredient Facts
2-Chloro-p-Phenylenediamine
AKA: 4-diaminobenzene, 4-Benzenediamine, 4-phenylenediamine, Ursol Brown O, 3-Chloro-4-aminoaniline, 4-Diamino-2-chlorobenzene, 4-benzenediamine, O-Chloro-p-phenylenediamine
Synthetic · Hair Dyeing · EWG: 4
Synthetic
Synthetic
Clean
A color-enhancing agent that helps hair dyes develop vibrant, long-lasting shades. Works as a key component in permanent hair coloring formulas.
Formula
C6H7ClN2
Mol. Weight
142.58
CAS #
615-66-7
Form
Liquid
State
Solid; [MSDSonline]
See origin →
Functions
Hair Dyeing
Colors Hair
Traditional Use
A synthetic aromatic amine developed as a hair dye intermediate in oxidative coloring systems. It was created in the 20th century as an alternative to plant-based dyes for permanent hair color.
Skin Types
●all-skin-types
Best For
General
Melanin-Rich Skin
Suitable
Pregnancy & Breastfeeding Safe
No
Final Report on the Safety Assessment of 2-Chloro-p-Phenylenediamine and 2-Chloro-p-Phenylenediamine Sulfate
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
2-Chloro-p-Phenylenediamine
European Commission
EU Cosmetic Ingredient Database (CosIng)
2-Chloro-p-Phenylenediamine Sulfate
European Commission
EU Cosmetic Ingredient Database (CosIng)
Allergic contact dermatitis from 2-chloro-p-phenylenediamine in a cream dye for eyelashes and eyebrows.
Hansson C, Thorneby-Andersson K
Contact dermatitis, 2001
1-Methoxy-2,4-diaminobenzene and its salts
Health Canada
Health Canada Cosmetic Ingredient Hotlist
Verified Feb 2026
Data: PubChem · CosIng · EWG · CIR