Ham hock & Chunky egg

What it is. A curing salt that keeps cured and processed meats pink and stops the growth of the bacteria behind botulism.

Why it is used. Used in bacon, ham, salami and hot dogs for preservation, safety and colour.

What the evidence says. The concern is not the additive in isolation but processed meat as a whole, which the WHO's cancer agency IARC classes as Group 1, meaning there is sufficient evidence it causes colorectal cancer. Nitrite can form nitrosamines during curing and cooking, and those are the likely culprit. Risk rises with how much processed meat you eat over time.

Permitted with strict maximum levels. The EU cut the allowed limits further from 2023 to reduce nitrosamine formation.

Assessed against IARC, EFSA, UK FSA. Full entry for E250

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. Fat derived emulsifiers, closely related to ordinary dietary fats.

Why it is used. One of the most used additives in food: bread, margarine, ice cream, cakes and sauces.

What the evidence says. The body handles these much as it handles other fats, and EFSA's re-evaluation raised no safety concern at the levels used. They sit in the same broad emulsifier and gut microbiome research question as the others, which remains unsettled.

Permitted without a numerical limit. The fat source is not always stated, which matters for some diets rather than for safety.

Assessed against EFSA. Full entry for E471

What it is. The orange pigments found in carrots and other vegetables, either extracted or made synthetically.

Why it is used. Colours margarine, soft drinks, dairy, and sweets.

What the evidence says. The same compound the body turns into vitamin A, and safe at the levels used in food. High dose beta-carotene supplements have been linked to harm in smokers, but those doses are far above anything a colour in food delivers, and conflating the two is a common mistake.

Permitted. The supplement findings apply to concentrated doses, not to food colouring.

Assessed against EFSA, JECFA. Full entry for E160A

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

What it is. A fibre made by fermenting sugars with a bacterium, which thickens liquids at very low doses.

Why it is used. Thickens sauces and dressings and gives structure to gluten free baking.

What the evidence says. Passes through largely undigested and is treated as safe by regulators, with no numerical intake limit. Very large amounts act as fibre does, which is a digestive effect rather than a safety one.

Permitted freely.

Assessed against EFSA, JECFA. Full entry for E415