E-numbers / Preservatives / E213
also: Calcium salt of benzoic acid · INS 213
A synthetic preservative that stops mould, yeast and bacteria growing, used mainly in acidic drinks, sauces and fruit products.
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In a controlled trial, a mixture of food colours and sodium benzoate (the same family as E213) was linked to increased hyperactivity in young children.
Why it’s worth knowing. In a controlled trial, a mixture of food colours and sodium benzoate (the same family as E213) was linked to increased hyperactivity in young children. Benzoates can also trigger asthma-like reactions in people with aspirin sensitivity, and when E213 appears alongside vitamin C in a drink exposed to heat or light, small amounts of benzene, a Group 1 carcinogen, can form. High consumers, particularly young children, can exceed the acceptable daily intake for the whole benzoate group at typical use levels.
Calcium benzoate is the calcium salt of benzoic acid, a compound that occurs naturally in cranberries, plums, cinnamon and other berries at low levels. As a food additive it is produced synthetically. It belongs to the benzoate family alongside sodium benzoate (E211) and potassium benzoate (E212). Its body is converted to hippuric acid and cleared in urine within about 24 hours.
Benzoic acid, once released from calcium benzoate in water, moves into microbial cells and disrupts their internal pH, blocking the enzymes they need to produce energy. This kills or halts the growth of moulds, yeasts and some bacteria. The mechanism works best in acidic conditions, below about pH 4.5, which is why the additive is used mainly in soft drinks, fruit products and vinegars.
Soft drinks and fruit-based drinks, concentrated fruit juice, syrups, pickled vegetables, olives, sauces, marinades, jams, bakery products and some condiments. On a UK ingredients label it appears as 'calcium benzoate' or 'E213'.
A randomised controlled trial funded by the UK Food Standards Agency gave children aged 3 and 8-9 a drink containing sodium benzoate (the same chemical family as E213) plus one of two mixtures of artificial colours. Both mixtures increased hyperactivity scores compared with placebo, though the effect was not identical across age groups or mixtures. The study could not isolate the benzoate from the colours, so the size of benzoate's own contribution is uncertain. EFSA concluded the evidence was limited but did not rule it out.
Children aged 3 and 8-9 given drinks containing sodium benzoate plus artificial colours showed increased hyperactivity compared with placebo in a double-blind crossover trial.
EFSA's AFC Panel concluded the McCann study provided limited evidence of a small effect on activity and attention in some children, but found results inconsistent across age groups and additive mixtures, and did not change the ADI for sodium benzoate.
When a benzoate salt and ascorbic acid (vitamin C) are both present in a drink, and the drink is exposed to heat or light, a decarboxylation reaction can produce small amounts of benzene. Benzene is classified by the IARC as a Group 1 carcinogen, meaning it causes cancer in humans, specifically acute myeloid leukaemia. The FDA found levels above 5 parts per billion, the US drinking-water standard, in 10 of 200 soft drinks tested in 2005. Many manufacturers subsequently reformulated to reduce the risk.
Benzene can form in beverages containing benzoate salts and ascorbic acid, particularly under heat and light exposure, through decarboxylation of benzoic acid catalysed by trace metal ions.
IARC classifies benzene as Group 1 carcinogenic to humans, with sufficient evidence it causes acute myeloid leukaemia.
Benzoates have long been associated with pseudo-allergic reactions, meaning reactions that mimic allergy but do not involve the usual immune pathway. Studies in people with asthma, chronic urticaria or aspirin intolerance have shown that sodium benzoate can trigger histamine and prostaglandin release from gastric tissue in sensitised individuals. Roughly 3-6% of people with aspirin-intolerant asthma report reactions to benzoates. The reaction is not a true allergy and does not show up on standard allergy skin tests.
Sodium benzoate provoked release of histamine and prostacyclin from gastric mucosa in 29 patients with asthma, atopic dermatitis or chronic urticaria; control tissue did not react.
Among asthmatics with the triad of aspirin intolerance, asthma and nasal polyposis, approximately 3-6% show intolerance to benzoate in oral provocation testing.
EFSA's 2016 re-evaluation of the whole benzoate group (E210-E213) set a group acceptable daily intake of 5mg per kilogram of body weight per day. Its own dietary exposure modelling found that high-consuming toddlers and young children in some European countries could reach up to 10.9mg/kg body weight per day from permitted food uses alone, more than double the ADI. High-consuming older children and adolescents reached up to 7mg/kg/day. EFSA concluded genotoxicity and carcinogenicity were not concerns at these levels, but flagged the exceedance as a reason for ongoing attention.
EFSA set a group ADI of 5mg/kg body weight per day for benzoic acid and its salts (E210-E213). High-consuming toddlers and young children showed estimated exposures of up to 10.9mg/kg/day, exceeding the ADI in some countries.
EFSA concluded that the available data did not indicate genotoxic or carcinogenic potential for benzoic acid and its salts when used as food additives.
People with aspirin-intolerant asthma, chronic urticaria or known benzoate sensitivity should check labels for 'calcium benzoate' or 'E213'. Parents of young children who are high consumers of soft drinks and fruit-based drinks may wish to moderate intake given the potential for the benzoate group ADI to be exceeded at high consumption levels. Anyone concerned about benzene formation should check whether a product also contains ascorbic acid or vitamin C, and store it away from heat and direct light.
E213 is part of the benzoate family, the most widely used class of food preservatives for acidic products. The core concern is not about a single alarming toxicity finding but a cluster of real, if bounded, signals. The 2007 McCann trial showed increased hyperactivity in children given a mix of colours and benzoate, but the study could not separate the benzoate from the colours, so the benzoate's own contribution remains contested. EFSA's exposure modelling found that high-consuming children can exceed the group ADI at permitted levels, which is a concrete data gap. The benzene formation pathway is real chemistry, and benzene is genuinely carcinogenic, but the doses from drinks are low compared to other benzene exposures in daily life, and the food industry has largely reformulated to reduce co-occurrence with vitamin C. Benzoate sensitivity reactions in asthmatic individuals are well documented, affecting a meaningful minority. None of this amounts to a crisis, but the science is not settled either, particularly around children's exposure.
No. Calcium benzoate (E213) is an approved food additive in the UK under the assimilated EU Regulation 1333/2008. It is permitted in a range of food categories including soft drinks, sauces, pickled products and jams.
A 2007 controlled trial found that a combination of sodium benzoate (the same chemical family as E213) and artificial food colours increased hyperactivity in children aged 3 and 8-9. The study could not isolate the benzoate's specific contribution from the colours. EFSA assessed the evidence as limited and did not change the ADI for benzoates, but did not rule out a link. The six artificial colours in the trial were voluntarily phased out by UK manufacturers; the benzoate was not.
Calcium benzoate is used mainly in acidic foods and drinks where it works most effectively. Typical products include soft drinks, concentrated fruit juices, pickled vegetables and olives, sauces and marinades, jams, jellies and some bakery products. On the label it will appear as 'calcium benzoate' or 'E213'.
Yes. Calcium benzoate is a synthetic chemical compound and contains no animal-derived ingredients. It is suitable for vegan and vegetarian diets.
Last reviewed: 20 June 2026
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