Sorbic acid
A naturally derived preservative added to stop mould, yeast and bacteria growing in food. Widely used in cheese, wine, baked goods and soft drinks.
When sorbic acid and nitrite preservatives are used together in the same food, lab studies have produced mutagenic reaction products. Regulators have flagged this co-use as an unresolved data gap, with no real-food measurements yet submitted to address it.
What is it?
Sorbic acid is a short-chain unsaturated fatty acid, first isolated from unripe rowan berries (Sorbus aucuparia) in 1859. Today it is produced synthetically. It is colourless, odourless and only slightly soluble in water, which is why its salt form, potassium sorbate (E202), is more commonly used in water-based products. Both forms work identically once dissolved.
What does it do?
Sorbic acid works by penetrating microbial cell membranes in its undissociated (protonated) form. Inside the cell, the higher pH environment causes the acid to split into charged ions that cannot escape, acidifying the cell interior and disrupting the metabolic processes that generate energy. This stops mould, yeast and many bacteria from growing. It is most effective at pH below 6.5, making it well suited to acidic foods such as fruit products, pickles and wine.
Where you will see it
Sorbic acid and its salts are used in soft cheese, processed cheese, wine, cider, dried fruit, baked goods, soft drinks, yoghurt, pickles, jams and prepared salads. It is also used in some meat products alongside nitrite preservatives. On a UK label it appears as 'sorbic acid', 'E200', or 'preservative (sorbic acid)'. Its more common salt form, potassium sorbate, appears as 'E202'.
What the science says
Mutagenic reaction products with nitrite
In laboratory conditions, sorbic acid reacts with sodium nitrite to produce compounds, notably 1,4-dinitro-2-methylpyrrole (DNMP), that cause DNA damage and show mutagenic activity in bacterial tests. Sorbic acid and nitrite are both permitted in certain food categories and can be used at the same time, for example in some processed meat products. EFSA flagged in 2019 that no measurements of these reaction products in actual food have been submitted to the regulator, leaving the real-world risk uncharacterised.
Sorbic acid and sodium nitrite react at gastric pH to form direct-acting mutagens including ethylnitrolic acid and 1,4-dinitro-2-methylpyrrole, both of which show mutagenic activity in the Ames test.
EFSA noted that sorbic acid and nitrite can co-occur in the same food products, that the reaction products formed are mutagenic in vitro, and that no analytical data on levels of those products in real food had been submitted; the panel described this as an unresolved data gap.
Reproductive toxicity at high doses in rats
An extended one-generation reproductive toxicity study in rats found reduced body weight in second-generation pups, reduced ovary and uterus weights in first-generation females, and elevated liver weights in males, all at the highest dose levels tested. These findings were the basis for setting the acceptable daily intake. At doses relevant to typical human food exposure, these effects were not seen.
An OECD-compliant extended one-generation reproductive toxicity study in rats identified decreased F2 pup body weight gains as the critical endpoint, along with reduced ovary and uterus weights in F1 females and elevated liver weights in males at the highest dose.
From the benchmark dose analysis, EFSA derived a group ADI of 11mg sorbic acid/kg body weight per day for E200 and E202 combined, replacing a previous temporary ADI of 3mg/kg/day set in 2015 pending this additional study.
Neurotoxicity and immunotoxicity not fully tested
The pivotal animal study that underpins the current ADI excluded the cohorts designed to test neurotoxicity and immunotoxicity. EFSA accepted this because the dose levels where earlier studies had found neurodevelopmental effects exceeded the new benchmark dose. However, no immunotoxicity data were generated in the new study, and this remains a gap in the evidence base.
The EOGRTS submitted to EFSA omitted cohorts 2 (neurotoxicity) and 3 (immunotoxicity) without full justification; EFSA accepted the omission for neurotoxicity but the absence of immunotoxicity data was noted as a limitation.
Skin reactions in people with sensitive skin
Sorbic acid can cause a non-immunological contact urticaria, meaning a short-lived burning or redness at the point of contact that is not a true allergic reaction. It can also, less commonly, cause genuine allergic contact dermatitis in people who have become sensitised, mainly through repeated topical (skin-product) exposure. Reactions from food contact are reported but less well documented.
Sorbic acid produces non-immunological contact urticaria on the skin and perioral area; the response was only partially blocked by local antihistamine, indicating a pharmacological rather than immune-mediated mechanism.
Documented cases of allergic contact dermatitis from sorbic acid and potassium sorbate exist, mainly from topical pharmaceuticals and medical devices; testing methodology affects detection rates and the true prevalence of sensitisation may be underestimated.
Sorbic acid itself does not damage DNA
Multiple studies have tested sorbic acid directly in bacterial mutagenicity tests and human cell models and found no evidence of mutagenic or genotoxic activity. The concern with DNA damage relates specifically to its reaction products when combined with nitrite or, in some studies, with ascorbic acid and iron, not to sorbic acid in isolation.
Cyclic derivatives formed when sorbic acid reacts with amines under typical food processing conditions showed no mutagenic or genotoxic activity in the Ames test or in HeLa cell and plasmid DNA assays.
Decomposed products of potassium sorbate reacting with ascorbic acid in the presence of iron salts showed mutagenicity and DNA-damaging activity in vitro.
Where it stands with the regulators
Who should be careful
People with a known sensitivity to sorbic acid or potassium sorbate who experience skin reactions on contact should check ingredient lists for 'sorbic acid', 'E200', 'potassium sorbate' or 'E202'. Sorbic acid is not a declarable allergen under UK food law and does not require a warning in bold on the label.
The honest read
Sorbic acid has been used as a food preservative for over 70 years and its basic safety profile is well characterised. The ADI established by EFSA in 2019 is based on a new animal study and sits well above estimated intake levels for most people, including children. Two areas remain genuinely open. First, when sorbic acid or its salts are used at the same time as nitrite preservatives in food, laboratory studies have shown that mutagenic compounds can form, but no one has yet measured whether these compounds are present at meaningful levels in real food. This specific question was flagged by EFSA in 2019 and has not been publicly resolved. Second, the animal study that formed the basis for the current ADI did not include the tests for immune system effects, which is a gap in the dataset. Neither concern relates to sorbic acid used alone in the many foods where it appears without nitrites.
Related additives
Common questions
Is E200 banned in the UK?
No. Sorbic acid (E200) is approved for use in the UK under the assimilated EU Regulation 1333/2008, which is part of UK law following Brexit. It appears on the Food Standards Agency's approved additives list.
Is there a concern about sorbic acid being used alongside nitrite preservatives?
Yes, this is a documented scientific question. When sorbic acid and nitrite are combined, laboratory studies have produced mutagenic compounds. EFSA noted in 2019 that no measurements of these compounds in real food had been submitted to regulators. Both preservatives are permitted in some of the same food categories, including certain processed meat products. The real-world significance remains unresolved.
What foods contain E200?
Sorbic acid (E200) or its more common salt potassium sorbate (E202) can be found in soft and processed cheese, wine, cider, baked goods, soft drinks, dried fruit, yoghurt, pickles, jams, prepared salads and some processed meat products. On the label it appears as 'sorbic acid', 'E200', 'preservative (sorbic acid)', or in its salt form as 'potassium sorbate' or 'E202'.
Is E200 vegan?
Yes. Sorbic acid is produced synthetically and contains no animal-derived ingredients. It was originally isolated from rowan berries, but commercial production uses chemical synthesis. Both sorbic acid itself and its potassium salt (E202) are considered vegan.
Sources
- EFSA Panel on Food Additives and Flavourings: Opinion on the follow-up re-evaluation of sorbic acid (E200) and potassium sorbate (E202) as food additives, EFSA Journal 2019;17(3):5625
- EFSA ANS Panel: Scientific Opinion on the re-evaluation of sorbic acid (E200), potassium sorbate (E202) and calcium sorbate (E203) as food additives, EFSA Journal 2015;13(6):4144
- PubMed: Opinion on the follow-up of the re-evaluation of sorbic acid (E200) and potassium sorbate (E202) as food additives (PMC full text)
- Food Standards Agency: Approved additives and E numbers
- Food Standards Agency: Authorised Regulated Food and Feed Products for Great Britain - E200
- Formation of mutagens by sorbic acid-nitrite reaction: effects of reaction conditions on biological activities, Food and Cosmetics Toxicology, 1980
- Dendooven et al., Allergic contact dermatitis from potassium sorbate and sorbic acid in topical pharmaceuticals and medical devices, Contact Dermatitis, 2021
- Clemmensen and Hjorth, Perioral contact urticaria from sorbic acid and benzoic acid in a salad dressing, Contact Dermatitis, 1982
- Genotoxicity study of reaction products of sorbic acid, Journal of Agricultural and Food Chemistry, 2000
- Mutagenicity and DNA-damaging activity caused by decomposed products of potassium sorbate reacting with ascorbic acid in the presence of Fe salt, Food and Chemical Toxicology, 2002
- Commission Regulation (EU) 2024/2597 of 4 October 2024 amending Annex II to Regulation (EC) No 1333/2008 as regards the use of sorbic acid (E200) and potassium sorbate (E202), EUR-Lex
Aaron Keen is the founder of NutraSafe. He researches and writes every additive entry himself, from the primary sources. About the research →
This is a guide, not medical advice. If an additive affects you, speak to your GP or a dietitian.
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