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Calcium hydroxide

CAS 1305-62-0
72

Safety score · 0–100

Fine

Derived from EU CosIng regulatory status, PubChem hazard data and published research. How we score.

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

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, so always read the physical product label and consult a healthcare professional for personal concerns.