Science
Mechanism of Action
Functions as a coupler in oxidative hair dyeing systems, reacting with primary intermediates such as p-phenylenediamine in the presence of hydrogen peroxide to form large, colored molecules that become trapped within the hair structure for permanent color results.
Research
Clinical Evidence
High confidence2%
Key findings
- 01 SCCNFP/SCCS safety evaluation confirmed efficacy and safety at 2.0% concentration in hair dye formulations
- 02 SCCS 2007 assessment validated performance up to 1.5% in-use concentration with hydrogen peroxide dilution
Transparency
Dusting Analysis
Exclusively used in hair dye products at regulated concentrations; not applicable to general skincare formulations
The Formula
Formulation
Stability
Requires alkaline conditions for optimal performance; sensitive to premature oxidation from light and air exposure; typically requires airless packaging or protective formulation matrices
Synergies
- p-phenylenediamine
- hydrogen peroxide
- alkaline pH buffers
Conflicts
- strong oxidizing agents
- acidic pH conditions
Safety
Safety Profile
EU regulated under Annex III/19 with mandatory sensitization warnings; maximum 2.0% in dye component, 1.0% after developer mixing; requires patch testing recommendations
Your Skin
Skin Compatibility
Our Assessment
Verdict
A specialized hair dye ingredient with established safety at regulated concentrations, unsuitable for general skincare applications due to sensitization potential and specific alkaline pH requirements.
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References
Sources