Herring rolls with onion in rapeseed oil

What it is. The potassium salt of sorbic acid, which stops mould and yeast growth.

Why it is used. Used in cheese, baked goods, dried fruit, wine and dressings.

What the evidence says. Widely used and long regarded as one of the gentler preservatives. EFSA's 2015 re-evaluation lowered the acceptable daily intake and noted gaps in the genotoxicity data, asking for more work, while finding no evidence of harm at the levels actually used.

Permitted with maximum levels. EFSA has asked for further data rather than restricted it.

Assessed against EFSA. Full entry for E202

What it is. A preservative that stops yeasts, moulds and some bacteria growing in acidic foods.

Why it is used. Used in soft drinks, sauces, pickles and dressings.

What the evidence says. EFSA re-evaluated it in 2016 and kept an acceptable daily intake, with normal exposure below it. The known issue is specific: in acidic drinks that also contain vitamin C, benzoate can form small amounts of benzene, so manufacturers reformulated to avoid the combination. It was also present in the drink mixes used in the Southampton hyperactivity study, though the warning requirement that followed applies to the colours rather than to benzoate.

Permitted with maximum levels in the foods where it is allowed.

Assessed against EFSA, UK FSA. Full entry for E211

What it is. A preservative that stops browning and microbial growth.

Why it is used. Used in dried fruit, wine, some soft drinks and processed potato.

What the evidence says. Not a cancer concern, but a well established trigger for asthma symptoms and sensitivity in some people, which is why it is a declarable allergen. Clear, strong evidence, but the concern applies to a specific group rather than everyone.

Permitted, but must be declared on the label when above a small threshold because of the allergy risk.

Assessed against EFSA, UK FSA. Full entry for E220

What it is. Vitamin C, added to protect colour and flavour and sometimes to fortify.

Why it is used. Stops browning in juices and cut fruit, protects fats, and boosts vitamin content.

What the evidence says. Beneficial and harmless at the levels used. Included here as a reminder that an E number is just a code, and plenty of them are ordinary nutrients.

Permitted freely, no concern.

Assessed against EFSA, JECFA. Full entry for E300

What it is. A mild acid found naturally in citrus fruit, made commercially by fermentation.

Why it is used. Adds tartness, balances flavour and helps preserve. One of the most used additives in food.

What the evidence says. Safe at food levels. No credible health concern for the additive itself.

Permitted freely.

Assessed against EFSA, JECFA. Full entry for E330