1-NAPHTHOL is graded C (Moderate) by Expert·ING, based on COSING regulatory data. It is restricted under EU COSING — AnnexIII-SAFETY-.
1-NAPHTHOL
Safety grade: C
1-Naphthol is a chemical compound derived from naphthalene, a substance found in coal tar. It is used in hair coloring products to help create and develop color on the hair strand.
It is used in hair dye formulations as a color-coupling agent, reacting with other dye components to produce and fix lasting color in the hair.
Graded using: COSING.
- EU COSING — Restricted
- Health Canada — Restricted
Last verified: May 26, 2026
Safer alternatives to 1-NAPHTHOL
- 2-METHOXYMETHYL-P-PHENYLENEDIAMINE — Grade A. Oxidative dye intermediate that couples with oxidants to develop hair color
- 5-AMINO-6-CHLORO-O-CRESOL — Grade A. Phenolic compound functioning as color coupler in oxidative hair dye systems
- LAWSONIA INERMIS EXTRACT — Grade A. Plant extract with natural dye molecules that directly color hair fibers
Other Hair Dyeing ingredients
- RESORCINOL — Grade E**
- THYMOL — Grade A
- M-AMINOPHENOL — Grade C**
- P-AMINOPHENOL — Grade C**
- 2-METHYLRESORCINOL — Grade C
- 4-AMINO-2-HYDROXYTOLUENE — Grade C
- P-PHENYLENEDIAMINE — Grade D**
- 2-METHYL-5-HYDROXYETHYLAMINOPHENOL — Grade C