Potassium benzoate

Potassium benzoate is the potassium salt of benzoic acid (E210) and functions identically to its sodium counterpart (E211) as a preservative. It inhibits the growth of moulds, yeasts, and bacteria in acidic food and beverage products. Manufacturers sometimes prefer it over sodium benzoate when reducing the sodium content of a formulation, as the potassium cation replaces sodium while retaining the same antimicrobial action.

Potassium benzoate shares the JECFA group ADI of 5 mg per kilogram of body weight per day, expressed as benzoic acid equivalents. Like E210 and E211, it can react with ascorbic acid in acidic beverages to produce trace quantities of benzene. Most major beverage producers have reformulated to avoid this combination, but the risk remains relevant in beverages containing both a benzoate salt and added vitamin C.

Potassium benzoate is not permitted as a direct food additive in the United States and is used less frequently than sodium benzoate globally. In the EU and other markets where it is approved, the same caution applies as for E211. Looksee assigns an avoid rating due to the benzene formation pathway and the availability of safer alternative preservatives.