An additive is anything a manufacturer puts in food that isn't food: a colour, a preservative, a thickener, a sweetener. Most do a dull job. A few carry findings serious enough that UK law puts a warning on the pack. Here's how to tell them apart, and what to look for on the back of a packet.
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Something added to food to do a job the food can't do on its own. Stop it going mouldy. Stop the oil and water splitting. Hold a colour that would otherwise fade in the factory. Make it sweet without sugar. In the UK an approved additive gets a code, an E-number, so a label can print "E300" instead of "L-ascorbic acid". The code is a shorthand, not a verdict.
Almost always for shelf life, cost or consistency. A loaf that has to survive a lorry, a warehouse and five days on a shelf needs help a home kitchen never needs. Knowing which job an additive is doing tells you more than the code does, because the entries with findings against them sit in the colours and the preservatives.
Heat and light strip colour out during processing, so it goes back in. Some come from plants: curcumin from turmeric, the purple in grape skin. Some are man-made dyes. Six of those man-made colours carry a legally required warning on UK packs about children's behaviour.
Preservatives hold back mould and bacteria: sodium benzoate in soft drinks, sorbates in bread, sulphites in wine and dried fruit. Antioxidants stop fats going rancid and stop cut fruit browning, and are often just vitamin C or vitamin E. The nitrites that cure bacon and ham also sit in this group, and they are the ones with a cancer finding attached.
Sweeteners hit the same taste with almost no calories, which is how a diet drink works. Aspartame was classed "possibly carcinogenic" by IARC in 2023, and the WHO left the daily intake limit unchanged the same week.
Thickeners and the things that stop oil and water splitting apart. Lecithin in chocolate, xanthan in a dressing, modified starch in a sauce. This is also why a supermarket loaf is still soft on day five.
Flavour enhancers push savouriness up without more meat or stock. MSG is the obvious one. Yeast extract does much the same job and lets a label avoid printing MSG at all.
Sodium nitrite and its relatives (E249 to E252) cure most UK bacon, ham, salami and hot dogs. IARC classes processed meat as Group 1: it causes bowel cancer in humans. Group 1 is a statement about how certain the finding is, not about how large the risk is. The NHS caps processed meat at 70g a day.
A few carry published findings of harm. Most are ordinary ingredients doing a dull job. The difficulty is that one word covers vitamin C and a coal-tar dye.
Before an additive is allowed in UK food it is risk-assessed, given a daily intake limit, and permitted only in certain foods at certain levels. That is why "how much would I have to eat" is usually the more useful question than "is this on a list". But approval is a judgement made on the evidence available at the time, and the evidence moves. E171 (titanium dioxide) was permitted for decades. In 2021 EFSA said it could no longer rule out damage to DNA, and EU food dropped it the following year.
So the question worth asking in the aisle isn't "does this pack have E-numbers in it", because almost every packet does. It's "is one of the three flagged groups in here, and how often do I eat this". Three groups do most of the work, and you can learn them in a minute.
Six of them, linked to increased hyperactivity and inattention. Any UK pack containing one has to print a legal warning. See which six →
Nitrites in bacon, ham and salami sit inside the processed-meat finding that IARC classes as causing bowel cancer. The NHS caps processed meat at 70g a day.
E171 came out of EU food in 2022 over possible DNA damage. Great Britain still permits it, so it can appear on a UK shelf.
Not grades, and not a list of things to fear. Three documented regulator positions, written so you can spot them on a pack and decide for yourself.
E102, E104, E110, E122, E124, E129. Any UK product containing one of them must print the warning "May have an adverse effect on activity and attention in children." That wording is set in law, not written by us. Most UK brands reformulated to drop the colours, so where you still meet them is imported sweets, imported soft drinks and party food.
Source: FSA, Southampton study (2007); UK retained EU Regulation 1333/2008.
E249, E250, E251 and E252 cure ham, bacon, salami and hot dogs. IARC classes processed meat as Group 1: it causes bowel cancer in humans. The nitrite chemistry is part of the mechanism that review describes. The NHS caps processed meat at 70g a day.
Source: IARC Monograph 114; NHS Eatwell; SACN, red and processed meat.
A white colour used in icing, chewing gum and sauces. EFSA re-evaluated it in 2021 and could no longer rule out damage to DNA. EU food banned it from 7 August 2022. Great Britain kept it permitted, so it can still turn up here, and it remains in toothpaste and some medicines everywhere.
Source: EFSA re-evaluation (2021); EU Commission Regulation 2022/63; FSA GB position.
Some colours affect some children, enough that UK law puts a warning on the pack. Here's what the research found, and what it didn't.
A 2007 study at the University of Southampton tested six artificial colours, often alongside the preservative sodium benzoate, and found a link to increased hyperactivity and inattention in some children. It measured behaviour on rating scales. It did not diagnose ADHD, and not every child reacts.
The response was a warning rather than a ban. Any UK product containing one of the six must carry the wording "May have an adverse effect on activity and attention in children." Most UK brands reformulated instead of printing it, which is why the colours turn up now mainly on imported sweets, imported drinks and cheap party food.
If you are trying to work out whether it's your child, log what they ate and how they were afterwards, then take the pattern to your GP. In the app the colours are named on the food's added list with the legal wording alongside, on Pro. We don't diagnose.
Most people worrying about additives are really worrying about ultra-processed food. The two overlap, but they are not the same question.
NOVA, the classification used in most published research, doesn't count additives as harmful in themselves. It treats them as a marker. A long run of colours, sweeteners, thickeners and flavourings tells you the thing in your hand is an industrial formulation rather than a cooked meal, and that is what gets classed as ultra-processed.
SACN, the committee that advises the UK government on nutrition, reviewed the evidence in 2023. Its position was that the link between higher intake and worse health outcomes is concerning, but the studies are mostly observational and cannot yet separate the processing itself from the energy, saturated fat, salt and sugar these foods deliver. There is no UK regulation of ultra-processed food and no front-of-pack label for it, which leaves the ingredients list as the only tool a shopper actually has.
So a long additive list is a signal about how a food was made, not a verdict on every entry in it. Judge the food first, then check the two or three entries that carry findings.
Six things to look for on the back of a packet, in the order you'll meet them.
Recipes change without notice, and the ingredients list is the only place it shows. A product you checked last year may not be the same product now, which is why the habit worth building is checking the pack in your hand rather than remembering a brand.
And if you want the detail on one code rather than the whole label, the E-number list is searchable by code, by name, or by the food you saw it on.
Reading a label yourself works. It's just slow when you're holding two packets and a child. Here's the same job done off a barcode.
Scan a UK barcode and we read the ingredients line and pull out what's been added. Each entry gets its name, its code, what kind of thing it is, whether it came from a plant or a factory, and a line on what it does in your body where there's published research to say. The list sorts worst first, so on a pack of bacon the sodium nitrite sits above the citric acid rather than in ingredient order.
When our sources have nothing on an entry, the line stays empty. Silence there means we found nothing published, not that we checked it and cleared it.
The database covers UK products, branded and supermarket own-brand, with the real pack photo where we have one, so you can see you've got the right product before you read a word. Scanning a barcode, the product score and the count of what's been added are in the free tier. Naming each one and what it does to you is NutraSafe Pro, £3.99 a month, alongside vitamins and minerals against UK reference intakes, the AI meal scan, the AI Coach, fasting and workouts.
What we won't do is tell you to put the packet down. We put the finding and the source in front of you, and what you make of it is your call.
The questions we get most in supermarket-aisle messages and app submissions. Sourced to the FSA, EFSA, IARC, SACN and UK retained law.
Something a manufacturer puts into food to do a job the food can't do on its own: stop it going mouldy, stop the oil and water splitting, hold a colour that fades in processing, or make it sweet without sugar. In the UK an approved additive gets a code, an E-number, so the label can print "E300" instead of "L-ascorbic acid". Flavourings are regulated separately and often appear with no code at all.
A few carry published findings of harm. Most are ordinary ingredients doing a dull job. The difficulty is that the word "additive" covers vitamin C and a coal-tar dye equally. Three groups are worth recognising on sight: the six colours that carry a legal warning about children's behaviour, the nitrites used to cure bacon and ham, and E171, which is out of EU food. Approval isn't permanent either. E171 was permitted for decades before the 2022 ban.
The nitrites in bacon, ham, salami and hot dogs (E249 to E252) sit inside the processed-meat finding IARC classes as Group 1, causing bowel cancer in humans, and the NHS caps processed meat at 70g a day. Six colours known as the Southampton Six are linked to increased hyperactivity and inattention in some children, and UK law requires a warning on the pack. E171 titanium dioxide has been out of EU food since August 2022 after EFSA could no longer rule out damage to DNA, though Great Britain still permits it.
Six artificial colours are linked to increased hyperactivity and inattention in some children. A 2007 study at the University of Southampton tested them, often alongside the preservative sodium benzoate, and measured behaviour on rating scales. It did not diagnose ADHD, and not every child reacts. UK law now requires any product containing one of the six to carry the wording "May have an adverse effect on activity and attention in children."
Additives sit at the end of the ingredients list, because the list runs heaviest first. Each is printed as its job followed by its name or code in brackets, for example "Colour (E102)" or "Preservative (sodium nitrite)". Look under the list for the children's-behaviour warning. Treat "flavourings" as a catch-all, because the label never has to say what's under it. And "no artificial colours" on the front says nothing about the preservatives, sweeteners or thickeners in the list.
The code doesn't tell you which is which. E160a is beta-carotene, the orange in carrots. E110 is a dye first made from coal tar. Both carry an E-number because both were assessed for use in food. "Natural" on the front of a pack is a marketing word rather than a regulated one, so it tells you nothing about what's in the list.
No. Approved additives get an E-number, three digits sometimes followed by a letter. Flavourings sit under separate rules and can appear as just "flavourings" or "natural flavouring", naming nothing. Processing aids used during manufacture but not present in the finished food don't have to be declared at all.
E171 titanium dioxide, a white colour, has been banned in EU food since 7 August 2022 under Commission Regulation 2022/63, after EFSA concluded it could no longer rule out damage to DNA. Great Britain still permits it, so it can appear on a UK shelf. It also remains permitted across the EU and UK in toothpaste and some medicines. Current status for any additive is published by the FSA, with the underlying opinions at EFSA.
They're one of the markers, not the whole definition. The NOVA system used in most published research treats colours, sweeteners, thickeners and flavourings as a sign that a food is an industrial formulation rather than a cooked meal. SACN reviewed the evidence in 2023 and said the link between higher intake and worse health is concerning, while noting the studies can't yet separate the processing from the sugar, salt and fat these foods carry.
For most additives, more than a normal diet delivers. Regulators set a daily limit per kilogram of body weight, then cap how much can go into each food, and that second cap is what keeps ordinary eating under the first. The arithmetic doesn't apply to the processed-meat finding, which is about the food rather than a dose of one additive, and it doesn't apply to the children's-behaviour colours, where the response was a warning on the pack rather than a limit.
Read the ingredients list on the pack, where codes sit in brackets after the job word. Or scan the barcode in NutraSafe: the free tier gives you the product score and a count of what's been added, and NutraSafe Pro at £3.99 a month names each one and says what it does in your body, with the source. We compare twelve UK scanner apps, ours included, in the best food scanner apps UK roundup. To look up one code on its own, the E-number list on this site is open to everyone.
More on this, sourced the same way.
Scan a UK barcode and we pull out what's been added to the food, name each one in plain English, and put the research and the source next to it. Free download, and scanning is in the free tier. Naming what's in there is NutraSafe Pro, £3.99 a month.
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