Calcium benzoate

Calcium benzoate is the calcium salt of benzoic acid, used as a preservative in acidic food products to inhibit the growth of yeasts, moulds, and certain bacteria. It functions through the same mechanism as sodium benzoate (E211) and benzoic acid (E210): undissociated benzoic acid penetrates microbial cell membranes at low pH and disrupts intracellular processes. Its use is most effective in low-pH products such as beverages, fruit preparations, pickles, and condiments.

JECFA most recently re-evaluated benzoic acid and its salts in 2016 and maintained the group ADI of 5 mg/kg body weight per day expressed as benzoic acid. Calcium benzoate contributes to total benzoate intake and is included in this group assessment. The primary safety concern with benzoate preservatives in acidic, vitamin C-containing products is the potential for benzene formation: in the presence of ascorbic acid (vitamin C) and metal ion catalysts under acidic conditions, benzoic acid can be converted to benzene, a known human carcinogen, at low levels.

Calcium benzoate is approved in the EU and globally for use in specific food categories at defined maximum levels. Regulatory bodies have set strict maximum use limits for benzoate preservatives to maintain consumer exposure well below the group ADI, and manufacturers of acidic beverages containing both benzoate preservatives and ascorbic acid have been encouraged to reformulate or monitor for benzene formation. Consumers who wish to minimise benzoate intake may look for products using alternative preservatives such as sorbates. The calcium salt form is encountered less frequently than sodium benzoate (E211) in commercial food products.