Are E-numbers bad for you? Which ones the UK flags, and which are vitamins.

What an E-number actually is

An E-number is a code for a food additive that has been assessed for use in food across the UK and EU. The "E" stands for Europe. The system was retained in UK law after Brexit, so packs sold in British supermarkets still carry the same codes you see across the EU.

E-numbers cover preservatives, colourings, sweeteners, emulsifiers, antioxidants, thickeners and flavour enhancers. Some are synthetic. Some are extracted from plants. Some are vitamins. The code itself is just an identifier — it doesn't tell you what the additive is doing in the product, what it's made of, or whether published research has flagged it.

If you want to look up any individual code, our public database covers 330+ additives used in UK food: NutraSafe E-Numbers lookup. No app, no sign-in.

The Southampton Six — the colourings the UK flags for children

Six artificial food colourings carry a mandatory warning label in the UK. Products that contain any of them must display the line:

"may have an adverse effect on activity and attention in children"

This follows FSA guidance after the 2007 University of Southampton trial (McCann et al., The Lancet) commissioned by the Food Standards Agency. The trial gave around 300 children aged 3 and 8–9 a mixture of these six colourings plus sodium benzoate, and recorded a statistically significant rise in hyperactive behaviour compared with placebo. The six colourings:

Many UK manufacturers reformulated to drop these colourings in the years after the FSA recommendation. Some still use them. The warning label is the legal compromise — they're allowed in food, but the pack has to tell you. For a deeper read on this group, see our Southampton Six article.

Aspartame (E951) — IARC Group 2B

Aspartame is the sweetener in many diet drinks, sugar-free chewing gum and "no added sugar" desserts. Its regulatory status changed in July 2023.

The International Agency for Research on Cancer (IARC), the WHO body that classifies carcinogens, placed aspartame in Group 2B — possibly carcinogenic to humans. On the same day, the joint FAO/WHO Expert Committee on Food Additives (JECFA) reviewed intake data and kept the Acceptable Daily Intake at 40 mg per kg of body weight. Both rulings stand together: IARC says the evidence is suggestive, JECFA says current intake levels stay within their threshold.

The UK and EU regulatory position: aspartame remains permitted within the ADI. The science is unsettled — Group 2B is a category that says human evidence is limited, animal evidence is limited, and more work is needed. It is not the same as Group 1 (where processed meat sits) or Group 2A. We don't read 2B as a verdict in either direction; we report it as the WHO classified it.

If you log diet drinks or sugar-free products in our app, every product carrying E951 is surfaced with the IARC line and the JECFA ADI in plain English.

E-numbers that are vitamins or natural pigments

The flip side. Several codes you'll see on labels are the same molecules you find in fruit, vegetables, or a multivitamin tablet:

"Beetroot extract" sounds friendlier than E162 — but they are the same thing. The code on the label and the picture on a marketing flyer are describing the same molecule. The labelling system gives a consistent identifier across languages; it doesn't carry a verdict.

What the science doesn't yet know

One honest gap: most additive safety reviews look at single substances, one at a time, at typical intakes. Real food often combines several emulsifiers, sweeteners, colourings and stabilisers in the same product, and modern UK diets layer those products across the day. Research on these cocktail effects is younger and less complete than the per-additive dossiers — and ultra-processed-food cohort studies have raised questions that researchers are still working through.

What that means in practice: the regulatory status of an additive can shift. Titanium dioxide (E171) was permitted in EU food until 2022, then banned after EFSA could not rule out genotoxicity. Aspartame was uncontested for decades, then IARC moved it to Group 2B in 2023. We treat regulatory status as a snapshot, not a verdict — and we update this page as the picture changes.

How to spot E-numbers on a UK food label

UK and EU rules let manufacturers list additives by code (E102), by chemical name (Tartrazine), or by category and name (Colour: Tartrazine). The category comes first, so the label tells you what the additive is doing in the product. A few things to scan for on the back of a pack:

• Colour: followed by an E-number or chemical name. The Southampton Six show up here. Look for E102, E104, E110, E122, E124, E129.
• Sweetener: E951 is aspartame. E950 is acesulfame K. E955 is sucralose. Many "no added sugar" or "diet" products carry one of these.
• Preservative: sulphites (E220–E228) must be declared as an allergen above 10 mg/kg under UK rules — relevant for asthmatics with sulphite sensitivity.
• Emulsifier / stabiliser: codes in the E400s and E500s. Most are well-studied; some (E433 polysorbate 80, E466 carboxymethylcellulose) feature in current gut-microbiome research.

Or scan the barcode. We surface every E-number in the product, name it, explain what it does, and note any UK warning that applies — without you having to memorise codes.

Where we draw the line on advice

We're a tracking app, not a GP. We won't tell you to avoid a particular additive — that's a conversation between you and your doctor or dietitian, especially if a child is reactive to colourings or you're managing asthma or a known allergy. What we will do is name the additive, show what published research and UK regulators say, and let you log it so you can take the picture to a clinician if you want to.

For asthma and sulphites (E220–E228), reactions in sensitive individuals are well-documented; the NHS and FSA have specific guidance. For the Southampton Six and children's behaviour, the warning label exists for a reason. For aspartame, IARC classifies it Group 2B and JECFA keeps the ADI at 40 mg/kg — both are true at the same time, and both are worth knowing.

Frequently asked questions

Are all E-numbers bad for you?

No. Some are vitamins (E300 is vitamin C, E101 is vitamin B2). Some are natural pigments (E160a is beta-carotene). Others — the Southampton Six colourings, aspartame at IARC Group 2B — carry warnings or active scientific scrutiny. The code itself is just an identifier. What it is and what published research says is what matters.

Which E-numbers does the UK flag with a warning label?

Six colourings: E102 Tartrazine, E104 Quinoline Yellow, E110 Sunset Yellow, E122 Carmoisine, E124 Ponceau 4R, E129 Allura Red. Products containing any of them sold in the UK must show "may have an adverse effect on activity and attention in children" on the pack, per FSA guidance.

Is aspartame (E951) bad for you?

In July 2023 the IARC classified aspartame as Group 2B — possibly carcinogenic to humans. JECFA reviewed intake at the same time and kept the ADI at 40 mg/kg body weight. It remains permitted in UK and EU food within that limit. The science is still being reviewed.

Which E-numbers are actually just vitamins?

E300 is ascorbic acid (vitamin C). E101 is riboflavin (vitamin B2). E160a is beta-carotene from carrots, which the body converts to vitamin A. E306 is tocopherols (vitamin E). E322 is lecithin, often from soya. They're identical to the vitamins in a multivitamin or a vegetable.

How can I spot E-numbers on a UK food label?

Read the back-of-pack ingredient list. UK rules let manufacturers list additives by E-number, by chemical name, or both, with the category (Colour, Sweetener, Preservative) shown first. Scanning a barcode in our app surfaces every E-number in plain English. The public lookup at /e-numbers/ works without the app.

Related reading

• What are E-numbers? UK guide
• The Southampton Six and children's behaviour
• NutraSafe E-Numbers lookup (330+)
• Food additive scanner UK
• UPF scanner UK

Last reviewed: 7 May 2026.