Sodium hydroxide is a white crystalline substance, soluble in water. In cosmetics it is used for its function of buffer agent, pH regulator.
Sodium hydroxide is a white crystalline substance, soluble in water. In cosmetics it is used for its function of buffer agent, pH regulator. Being highly irritant at high concentrations, it is included in the list of substances whose use is permitted in cosmetic products with certain conditions of use and maximum concentrations:
- 5 % by weight, in the solvents for the nail cuticles
- 1.2 % by weight, in hair straightening products
- in the quantity sufficient to reach pH 12.7 as a pH regulator in depilatory products
- in the quantity sufficient to reach pH 11 as a pH regulator in other cosmetic products.
