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Moumoujus

2,6-BIS(2-HYDROXYETHOXY)-3,5-PYRIDINEDIAMINE HCL.

Avoid CAS 117907-42-3 / HAIR DYEING

A specialized pyridine derivative functioning as an oxidative hair dye coupler that creates permanent color through chemical reactions with hydrogen peroxide. This water-soluble compound penetrates the hair shaft to form stable pigment molecules, but requires strict acidic conditions and concentration limits for safe application. While effective for hair coloring applications, its use in skincare formulations is extremely limited due to regulatory restrictions and potential sensitization concerns.

Summary

hair dyeing oxidative coupler

Science

Mechanism of Action

Functions as a reactive coupler in oxidative hair dye systems, chemically bonding with primary intermediates in the presence of hydrogen peroxide to generate large, trapped pigment molecules within the hair cortex structure.

Research

Clinical Evidence

High confidence
Effective range 0.25–0.25%
Optimal

0.25%

Key findings

  1. 01 SCCS safety evaluation established 0.25% as maximum safe on-head concentration for effective oxidative hair dyeing
  2. 02 Animal studies at 3.0% concentration demonstrated absence of skin irritation and dermal sensitization in repeated application protocols

Transparency

Dusting Analysis

Commonly dusted
Min. effective
0.1%
Red flag below
0.25%

Heavily regulated ingredient with strict 0.25% maximum concentration limits; any higher percentages indicate regulatory non-compliance and potential safety violations

The Formula

Formulation

Solubility
Water
Optimal pH 1 – 3
0 7 14

Stability

Exhibits rapid degradation in neutral to alkaline environments with approximately 10% loss within 2-7 days at ambient temperature; maintains stability exclusively under strongly acidic conditions

Synergies

  • hydrogen peroxide
  • acidic pH adjusters

Conflicts

  • strong bases
  • alkaline buffers
  • uncontrolled oxidizing agents

Safety

Safety Profile

CIR Status
Safe with restrictions
Max tested
0.25%
Pregnancy
Caution
Sensitization risk Moderate

Regulatory approval limited to hair dye applications only; potential sensitization risk requires patch testing protocols for sensitive individuals

Your Skin

Skin Compatibility

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

Our Assessment

Verdict

Avoid

Specialized hair dye ingredient with no validated skincare applications and strict regulatory limitations that make it unsuitable for precision skincare formulations.

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