DIHYDROXYINDOLINE is graded C (Moderate) by Expert·ING, based on COSING regulatory data. It is restricted under EU COSING — AnnexIII-SAFETY-.
DIHYDROXYINDOLINE
Safety grade: C
Dihydroxyindoline is a chemical compound used in hair dyes that helps create color by reacting with other dye components. It works as a key building block that develops the final hair color shade through oxidation.
This ingredient is used in hair dyes as an oxidative dye precursor that develops and produces color when mixed with other dye molecules and oxidizing agents, allowing hair to be tinted in various shades.
Graded using: COSING.
- EU COSING — Restricted
Last verified: May 26, 2026
Safer alternatives to DIHYDROXYINDOLINE
- BASIC BROWN 17 — Grade A. Direct synthetic hair dye precursor that develops color via oxidation like dihydroxyindoline.
- BASIC BLUE 99 — Grade A. Oxidative dye molecule that produces color when mixed with developers in hair formulations.
- BASIC RED 51 — Grade A. Oxidative hair dye precursor that generates red tones through developer activation.
- 2-METHOXYMETHYL-P-PHENYLENEDIAMINE — Grade A. Aromatic amine oxidative dye intermediate that develops permanent hair color with peroxide.
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