Get a Free 5ml Mini Now Free 5ml Mini With Every Order of The Mantle
Moumoujus

PYROCATECHOL.

Avoid CAS 120-80-9 / HAIR DYEING

Pyrocatechol is a phenolic compound primarily recognized for its role as a precursor in oxidative hair dyeing systems. Despite theoretical discussions of its antioxidant potential at exceedingly low concentrations, its use in precision skincare is strictly prohibited. This is due to severe safety concerns, including its documented ability to induce skin depigmentation and provoke strong contact dermatitis reactions.

Summary

Science

Mechanism of Action

While Pyrocatechol theoretically functions as an antioxidant by scavenging free radicals at extremely low concentrations, this property is not safely applicable in skincare. In its primary commercial use, such as permanent oxidative hair dyes, it serves as a precursor that undergoes oxidation by hydrogen peroxide, leading to the formation of colorant molecules within the hair fiber. On the skin, its documented effects include irritation and pigment disruption.

Research

Clinical Evidence

Low confidence
Effective range N/A
Optimal

N/A

Key findings

  1. 01 Concentrations of 3.0% and 7-10% induced significant to very strong depigmentation in rabbit skin.
  2. 02 Human patch tests at 0.1%, 0.5%, and 2% concentrations caused strong positive reactions for contact dermatitis.

Transparency

Dusting Analysis

Not commonly dusted
Red flag below
0.1%

Pyrocatechol is explicitly classified as unsafe for use in leave-on cosmetic formulations, with a maximum allowable concentration of 0%. Concentrations as low as 0.1% have been demonstrated to cause strong contact dermatitis in humans, while higher levels (3.0% and above) induce significant depigmentation. Given these severe risks and regulatory prohibitions, it is not considered safe or appropriate for any beneficial skincare application, making 'dusting' irrelevant.

The Formula

Formulation

Solubility
Water
Optimal pH N/A
0 7 14

Stability

Pyrocatechol presents as a white crystalline solid but discolors to brown upon exposure to air and light, indicating sensitivity. It forms acidic aqueous solutions and requires storage in a cool, dry place, shielded from direct sunlight and heat sources to maintain chemical stability.

Conflicts

  • strong oxidizers
  • strong acids
  • bases
  • acid anhydrides
  • alkali compounds
  • air
  • light

Safety

Safety Profile

CIR Status
Unsafe with restrictions
Max tested
0%
Sensitization risk High

The CIR Expert Panel concluded Pyrocatechol is unsafe for leave-on cosmetic formulations due to significant skin absorption. Health Canada, the European Union (listed in Annex II), and the FDA prohibit its use in cosmetics. The International Agency for Research on Cancer (IARC) has classified it as Group 2B (possibly carcinogenic to humans), and it is recognized by California's Prop 65 as a carcinogen.

Your Skin

Skin Compatibility

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

Our Assessment

Verdict

Avoid

Pyrocatechol carries significant health risks including severe skin irritation, depigmentation, and potential carcinogenicity, rendering it unsuitable and prohibited for any cosmetic application in precision skincare.

Related

Similar Ingredients

Finding similar ingredients…

References

Sources