Sodium benzoate

Sodium benzoate is the sodium salt of benzoic acid. It is a white, crystalline powder that is soluble in water. It occurs naturally in small amounts in fruits like cranberries and plums, but is typically produced industrially by reacting toluene with oxygen and then neutralising the resulting benzoic acid with sodium hydroxide.

Sodium benzoate is used as a preservative in a wide variety of foods and drinks. It is particularly effective in acidic conditions, where it works by inhibiting the growth of bacteria, yeasts, and moulds. It is commonly found in soft drinks, fruit juices, jams, pickles, and sauces.

Sodium benzoate is an authorised food additive in Great Britain, listed on the Register of Food Additive Authorisations. European bodies like EFSA have evaluated its safety. JECFA has evaluated it and set an acceptable daily intake. While generally considered safe at typical consumption levels, some studies have explored potential links between sodium benzoate and hyperactivity in children, though evidence is mixed and regulatory bodies have not established a causal link at permitted levels. It can also react with ascorbic acid (Vitamin C) to form small amounts of benzene, a potential carcinogen, particularly under conditions of heat and light; however, levels are generally very low and considered safe by regulatory agencies.