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Moumoujus

2-HEXYLOXYCARBONYL-P-PHENYLENEDIAMINE HCL.

Avoid CAS 2328127-45-1 (free base) / HAIR DYEING

A modified p-phenylenediamine derivative that serves as a primary intermediate in oxidative hair coloring systems. This compound requires alkaline conditions and hydrogen peroxide to activate, forming reactive quinoneimines that bind with coupling agents to create permanent hair pigments. While effective for hair dyeing applications, it carries significant sensitization risks and is strictly regulated for cosmetic use.

Summary

hair dyeing oxidative dye intermediate

Science

Mechanism of Action

Functions as an oxidative dye precursor that transforms into reactive quinoneimine intermediates under alkaline conditions with hydrogen peroxide, subsequently coupling with other agents to form large, stable pigment molecules that penetrate and remain trapped within hair structures

Research

Clinical Evidence

High confidence
Effective range 0.1–2%
Optimal

2%

Key findings

  1. 01 SCCS/1443/11 established 2.0% as maximum safe concentration for on-head applications
  2. 02 European patch testing protocols confirm sensitization potential at 0.1-1.0% concentrations

Transparency

Dusting Analysis

Not commonly dusted
Red flag below
2%

Not applicable for dusting analysis as this ingredient is exclusively used in hair coloring applications and prohibited in skincare formulations due to extreme sensitization risks

The Formula

Formulation

Solubility
Water
Optimal pH 8 – 10
0 7 14

Stability

Extremely sensitive to oxidation and rapidly darkens when exposed to air or moisture; remains stable only in acidic or inert environments until intentional activation

Synergies

  • Hydrogen peroxide (oxidizing activation)
  • Resorcinol (coupling agent)
  • Ammonia (alkaline activator)

Conflicts

  • Oxidizing agents (premature activation)
  • Strong acids (precipitation risk)
  • Iron salts (catalytic oxidation)

Safety

Safety Profile

CIR Status
Safe with restrictions
Max tested
2%
Pregnancy
Caution
Sensitization risk High

Strictly prohibited for eyelash/eyebrow dyes and dermal coloring applications; requires patch testing before use due to severe allergic contact dermatitis potential

Your Skin

Skin Compatibility

Yes Normal
Yes Dry
Yes Oily
No Sensitive
Irritancy High
Comedogenicity Unknown

Our Assessment

Verdict

Avoid

Effective hair dyeing ingredient with severe sensitization risks that make it unsuitable for precision skincare applications.

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