EWG level: 3
This is a highly caustic and reactive inorganic base. Sodium Hydroxide, Calcium Hydroxide, Magnesium Hydroxide and Potassium Hydroxide are white solids which occur in several forms, including powders. In cosmetics and personal care products, Sodium, Calcium, Magnesium and Potassium Hydroxide are used in the formulation of bath products, cleansing products, fragrances, foot powders, hair dyes and colors, makeup, nail products, personal cleanliness products, shampoos, shaving products, depilatories, skin care products, and suntan products. Sodium and Calcium Hydroxide are also used in hair straighteners and hair wave sets. Sodium Hydroxide has historically been used to hydrolyze fats and form soaps. It is also called caustic soda, soda lye or sodium hydrate.Calcium Hydroxide is also know as hydrated lime. The mineral form of Calcium Hydroxide is called portlandite. Magnesium Hydroxide is also know as milk of magnesia. The mineral form of Magnesium Hydroxide is called brucite. Potassium Hydroxide is also known as potash lye or caustic potash. Potassium Hydroxide has the ability to attract water molecules from the surrounding environment and eventually dissolves in the water it absorbs.
Its functions are: Denaturant; pH Adjuster; Buffering
“Restricted in cosmetics (recommendations or requirements) – use, concentration, or manufacturing restrictions” (CosIng)