Science
Mechanism of Action
Functions through structural ionization that responds to environmental pH changes, transitioning between yellow monoanionic form below pH 3.8 and blue-green dianionic form above pH 5.4. May modulate prostaglandin E2 levels through prostaglandin transporter inhibition, though this mechanism is primarily utilized in research applications rather than consumer skincare.
Research
Clinical Evidence
Medium confidence0.1%
Key findings
- 01 Scientific Committee on Cosmetology safety evaluation (1984) - no skin/eye irritation or sensitization at tested concentrations
- 02 Finnegan et al. (2022) - successful application in wearable pH monitoring sensors
Transparency
Dusting Analysis
Specialized ingredient with limited cosmetic applications, primarily used for specific color-changing or diagnostic functions rather than broad skincare benefits
The Formula
Formulation
Stability
Sodium salt form provides water solubility while free acid form dissolves in ethanol and organic solvents. Maintains stability at normal temperatures but degrades above 60°C.
Conflicts
- Strong oxidizing agents
- Strong acids (triggers yellow shift)
- Ammonia/Strong bases (triggers blue shift)
Safety
Safety Profile
Permitted colorant under EU Annex IV regulations. Limited to 0.1% in leave-on products and 0.4% in rinse-off formulations. Listed as reportable ingredient in California Safe Cosmetics Program due to environmental persistence concerns.
Your Skin
Skin Compatibility
Our Assessment
Verdict
A specialized colorant with unique pH-responsive properties that serves specific formulation needs rather than providing broad skincare benefits.
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References
Sources