Are food additives safe? A plain-English guide to E-numbers

What is an E-number?

A food additive is something added to food to do a job — keep it fresh, stop it separating, colour it, sweeten it, and so on. An E-number is simply the code given to an additive that has been assessed for safety and approved for use; the "E" originally stood for Europe, and the system was kept in UK law after Brexit.

The Food Standards Agency (FSA) groups approved additives into a handful of families, including colours, preservatives, antioxidants, sweeteners, and emulsifiers, stabilisers, gelling agents and thickeners, alongside others like acidity regulators and anti-caking agents. So "E-number" covers everything from vitamin C (E300, an antioxidant) to the colouring in a fizzy drink — the label doesn't tell you which is which, only that it's on the approved list.

Who decides they're safe?

Additives don't reach the shelf on trust. The FSA is clear that "additives must be assessed for safety before they can be used in food," and that an additive is only approved if it has been tested and proven safe for its intended use, there's a justifiable technological need for it, and its use doesn't mislead you.

Much of the underlying science comes from the European Food Safety Authority (EFSA), whose experts carry out risk assessments looking at an additive's chemical and biological properties, potential toxicity and how much of it people are likely to eat. Where the evidence allows, they set an Acceptable Daily Intake (ADI) — described by the NHS as "the maximum amount considered safe to consume each day over the course of your lifetime." Crucially, safety isn't decided once and forgotten: EFSA is re-evaluating every additive approved before 2009, and has so far reviewed more than 70% of the 315 additives on that list against the latest science.

"Approved" doesn't mean "eat unlimited"

This is the part the "all natural / no nasties" marketing skips. Approval is conditional. As the official approved-additives guidance puts it, "most additives are only permitted to be used in certain foods and are subject to specific quantitative limits." The ADI is set with a wide safety margin and takes into account where and how much an additive is allowed to be used, so you don't need to track it yourself — but it does mean approval is about using an ingredient sensibly, not a promise that any amount is fine.

It's also worth knowing that some people are simply more sensitive to particular additives than others, which is one reason the rules single a few out for extra labelling.

The six colours with a warning

If you want one concrete example of an additive worth avoiding for some people, it's this. Six artificial colours are linked to increased hyperactivity in some children, so any food or drink containing them must carry the warning: "may have an adverse effect on activity and attention in children." They are:

• Sunset yellow FCF (E110)
• Quinoline yellow (E104)
• Carmoisine (E122)
• Allura red (E129)
• Tartrazine (E102)
• Ponceau 4R (E124)

Many UK manufacturers have already reformulated to avoid them, which is why you'll often see natural colourings used instead. If hyperactivity is a concern for your family, these six are the names to look for on a label — and exactly the kind of thing Scrannr can flag for you.

What about sweeteners?

Sweeteners get a lot of worried headlines, so it's worth being precise. The NHS states that "all sweeteners in Great Britain undergo a rigorous safety assessment before they can be used in food and drink," and that "all approved sweeteners are considered a safe and acceptable alternative to using sugar."

The one genuine caveat is aspartame (E951): it isn't suitable for people with the rare inherited condition PKU (phenylketonuria), because they can't process a substance it contains (phenylalanine). That's why products with aspartame must carry a specific warning that they're a source of phenylalanine — a good reminder that "safe for almost everyone" and "safe for everyone" aren't always the same thing.

A sensible way to think about it

Put it together and the picture is calmer than the packaging suggests. An E-number on its own isn't a red flag — it usually means "tested and approved." At the same time, a very long additive list is often a sign of a more ultra-processed product, and a few additives (like those six colours) are worth avoiding for some people. The useful habit isn't fearing every code; it's noticing the overall pattern.

That's the job Scrannr does for you: it reads the ingredient list, flags the additives worth a second look in plain English, and folds that into a single health score so you don't have to memorise a list of numbers in the aisle.

Not medical advice. This guide is general information, checked against NHS, EFSA and Food Standards Agency guidance. It isn't a substitute for advice from a qualified professional. If you have a food allergy, intolerance or health condition, read the product label and speak to your GP, pharmacist or a registered dietitian.