What E-Numbers Actually Mean — And Which Ones Are Worth Avoiding

Turn over a packet of biscuits and you get something like this: sugar, palm oil, wheat flour, E322, E500, E330, natural flavouring. Four of those you recognise. Three of them are codes. And the codes are the part that decides whether you put the packet back on the shelf or in the trolley.

The reflex most people have is that E-numbers are the bad stuff. That reflex is wrong, and it is wrong in a way that costs you twice: you end up avoiding things that are completely benign, while walking straight past the handful that regulators have genuinely acted on.

Here is what the system actually is, and where the real concerns sit.

An E-number is a filing code, not a warning

The E stands for Europe. When an additive is assessed and approved for use in the EU it gets a number, and that number is a permanent identifier — nothing more. It tells you the substance has been through an approval process. It tells you nothing about whether it is natural, synthetic, harmless or contested.

Two examples make the point better than any explanation:

• E300 is ascorbic acid. Vitamin C.
• E330 is citric acid. The thing that makes a lemon a lemon.

Both look exactly as intimidating on a label as E951 (aspartame) or E250 (sodium nitrite). The numbering gives you no way to tell them apart, which is precisely the design flaw that makes labels unreadable for normal people. The system was built for regulators and manufacturers, and it works perfectly well for them. It was never built for someone standing in an aisle deciding what to feed their kids.

A rough guide to the ranges helps a little:

• E100–E199 — colours
• E200–E299 — preservatives
• E300–E399 — antioxidants and acidity regulators
• E400–E499 — thickeners, stabilisers and emulsifiers
• E500–E599 — acidity regulators and anti-caking agents
• E600–E699 — flavour enhancers
• E900–E999 — sweeteners, glazing agents and the rest

Useful, but not decisive. The concerning ones and the trivial ones sit side by side inside the same ranges.

Why "approved" does not mean "no concerns"

This is the part that trips people up. Approval is not permanent, and it is not unanimous. Safety assessments get revisited as new evidence arrives, and additives do get pulled.

The clearest recent case is titanium dioxide (E171), a whitener used in icing, chewing gum and sweets. In 2021 the European Food Safety Authority concluded it could no longer establish a safe daily intake, because it could not rule out genotoxicity — DNA damage — from the nanoparticles. The EU banned it in food in 2022. It had been approved and in widespread use for decades before that.

So "it is approved" means "no regulator has yet acted", not "science has settled this". Both of those are reasonable things to know when you are choosing between two jars of sauce.

The colourings with a legally required warning

If you remember one thing from this article, make it this group.

Six synthetic azo-type dyes are legally required in the EU to carry the statement "may have an adverse effect on activity and attention in children". That warning exists because of the 2007 Southampton study, which found effects on hyperactivity in children from mixtures of these colourings.

• E102 — Tartrazine (yellow)
• E104 — Quinoline Yellow
• E110 — Sunset Yellow
• E122 — Azorubine / Carmoisine
• E124 — Ponceau 4R
• E129 — Allura Red

The warning is on the packet by law, but it is in small print and it does not name the numbers in a way most shoppers connect to the ingredient list. If you have children, these six are the highest value codes to actually memorise. They cluster in sweets, fizzy drinks, jellies and brightly coloured snacks — exactly the products aimed at children.

A few related colourings sit outside that six but carry their own history: E123 (Amaranth) has been banned in the United States since 1976 over cancer concerns, and E127 (Erythrosine, Red No. 3) was linked to thyroid tumours in animal studies and had its US food authorisation revoked in 2025.

The cured-meat preservatives

E249, E250, E251 and E252 — the nitrites and nitrates — are what keep ham, bacon, salami and hot dogs pink and shelf-stable.

The nuance here matters, because this is the additive group most often reported badly. The nitrite itself is not classified as a carcinogen. What happened is that the International Agency for Research on Cancer classified processed meat as Group 1, carcinogenic to humans, and nitrosamines formed from these preservatives during curing and cooking are part of the proposed mechanism.

So the honest framing is not "E250 causes cancer". It is: processed meat carries an established risk, and these preservatives are implicated in why. Which is a good reason to treat charcuterie as an occasional food rather than a daily one — a conclusion most people have already heard, without knowing it had a number attached.

The sweeteners, where the evidence genuinely moved

Aspartame (E951) was classified by IARC in 2023 as Group 2B, "possibly carcinogenic to humans". That category is broader and weaker than headlines implied — it includes aloe vera extract and pickled vegetables — and the joint expert committee reviewing it left the acceptable daily intake unchanged. It is a flag, not an alarm. It also always carries a genuine warning for anyone with phenylketonuria, because it contains phenylalanine.

Sucralose (E955) picked up a newer concern: research on a breakdown product, sucralose-6-acetate, flagged DNA-damage potential, and sucralose degrades when heated, which makes baking with it a different proposition from stirring it into coffee.

More broadly, the World Health Organization advised in 2023 against using non-sugar sweeteners for weight control, having found no long-term benefit. That advice covers E950 (acesulfame K), E951, E954 (saccharin) and E955 as a class, and it is arguably more actionable than any individual additive's file.

The emulsifiers nobody was worried about ten years ago

This is the group where the science is actively moving, and it is worth watching precisely because these additives have a long, boring safety record on the older criteria.

Polysorbate 80 (E433), the related polysorbates (E432 and family), and carboxymethylcellulose (E466) are emulsifiers that keep ice cream smooth and sauces from separating. Research since around 2015 has shown effects on gut bacteria and the gut lining in animal models, with human trial work following. Carrageenan (E407) sits in similar territory, and EFSA set only a temporary acceptable intake for it pending more data.

Nothing here is settled and none of it is banned. But "the regulator has asked for more data" is genuinely useful information to have about the thickener in your daily yoghurt.

The aluminium cluster, which almost nobody notices

Scattered across unrelated ranges is a set of additives whose common factor is aluminium: E173, E520, E541, E554 and E555. They serve completely different purposes — colouring, firming, raising, anti-caking — so they never appear together and never look like a group.

EFSA's position is that aluminium intake should be minimised, because it accumulates in the body. The exposure that matters is cumulative across the whole diet, which is exactly the kind of thing a per-product label cannot show you.

And the large majority that are simply fine

It would be dishonest to write all of the above without saying clearly: most E-numbers are unremarkable, and treating the whole system as suspect is bad reasoning.

• E300 — ascorbic acid, vitamin C
• E330 — citric acid, naturally in citrus
• E440 — pectin, the setting agent in jam, from apples and citrus peel
• E322 — lecithin, usually from soy or sunflower
• E170 — calcium carbonate, chalk
• E160a — carotenes, the orange in carrots

And the most notorious of all, E621 — monosodium glutamate — is considered safe by EFSA at typical dietary levels. The "Chinese restaurant syndrome" panic that made its name was never substantiated. Some people do report headaches or flushing, which is worth respecting individually, but MSG's more useful signal is as a marker: it tends to appear in heavily processed food, and it is the company it keeps rather than the molecule itself that tells you something.

How to read a label in about ten seconds

You do not need to learn hundreds of codes. A working method:

1. Read the first three ingredients. They are listed by weight, so they are most of what you are eating. This single habit outperforms any additive knowledge.
2. Scan for the warning six — E102, E104, E110, E122, E124, E129 — especially on anything aimed at children.
3. Note the length of the list. Twenty ingredients where you expected five is itself the finding, whatever the individual codes are.
4. Look up the two or three you don't recognise. Not all of them. The unfamiliar ones.

That last step is the one that breaks down in practice, because you are standing in a shop, your hands are full, and typing "E466" into a search engine returns a chemistry paper.

If you want the lookup done for you

That specific gap is why we built TrueLabel, a free Android app that photographs an ingredient list, reads the text, and explains each additive it finds — what it is, what it does, and the public assessment behind any concern, in the same plain language as this article. It reads the printed label rather than looking up a barcode, so it works on supermarket own-brands and regional products that barcode databases have never heard of.

It is free, needs no account, and the analysis happens on your phone. TrueLabel on Google Play, or read how the scanner works first.

This article is informational and is not medical or dietary advice. Ratings and restrictions described here follow public assessments by EFSA, IARC/WHO and the peer-reviewed literature, and regulatory positions change over time. If you have a specific health condition or a diagnosed sensitivity, talk to a qualified professional.

Mentioned in this post: the free food-additive scanner.