Ingredient
Potassium Hydroxide
Caustic Potash
KOH
What it is
A strong inorganic alkali used in cosmetics in small, controlled amounts to adjust formula pH or, in cleansers, to react with fatty acids and form a soap-based surfactant.
How it works
Reacts stoichiometrically with fatty acids (saponification) to form potassium soap salts and raises pH toward the target range; in a rinse-off cleanser it is consumed almost entirely in this reaction rather than remaining as free alkali on skin.
What it does
Buffering
Concerns to know
-
Well tolerated
No significant safety concern is reported for this ingredient as used in cosmetics.