Calcium hydroxide
Safety score · 0–100
Fine
Derived from EU CosIng regulatory status, PubChem hazard data and published research. How we score.
About
A strong base used as a pH adjuster in cosmetic formulations, permitted up to 7% in rinse-off products with irritation warnings.
Calcium hydroxide (slaked lime) is an inorganic strong base widely used as a pH adjuster and formulation aid in cosmetic products. Under EU Cosmetics Regulation, it is permitted up to 7% in cosmetic formulations, particularly in hair straightening products and some skin care applications. As a strong base, it can cause skin and eye irritation at high concentrations but is well-tolerated at regulated levels in finished products.
Known concerns
- Skin and eye irritation at high concentrations
- pH adjuster requiring careful formulation
- Well-understood safety profile at permitted levels
References
EU CosIng database
European Commission cosmetic ingredient registry — regulatory status, restrictions, authorised functions.
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This profile is for educational purposes and does not constitute medical advice. Regulatory status and scientific understanding evolve — always read the physical product label and consult a healthcare professional for personal concerns.