Potassium Benzoate Bon Conservateur No known benefits Potassium Benzoate at a glance Sodium salt of benzoic acid Used as a preservative Also a food preservative Ruled safe as used in cosmetics and food Potassium Benzoate description Potassium benzoate is a potassium salt of benzoic acid. Considered synthetic, it’s used in cosmetics formulations as a preservative because of its antimicrobial properties. The independent Cosmetic Ingredient Review has ruled potassium benzoate safe in its current use in cosmetics, where it is used in concentrations up to 0.0003% in leave-on products. Potassium benzoate is also approved as a preservative in foods, where it has the U.S. Food and Drug Administration determination as Generally Recognized as Safe (GRAS). In its raw form, potassium benzoate is a white solid. Related ingredients: Sodium Benzoate