E Numbers: What They Actually Do, in Plain English

By David Hall, founder of IntoleranceLab · Updated August 2026

An E number is not a warning label. It is a code used for a food
additive that has an approved function, such as preserving, colouring,
thickening, sweetening or helping ingredients mix.

That does not mean every packaged food is identical, or that you have
to enjoy every ingredient. It does mean “contains E numbers” is not
enough information to decide whether a food is good or bad for you.

The Food Standards Agency explains that food additives are listed
using their functional class, such as an antioxidant or preservative,
followed by their specific name or E number. Food
Standards Agency: additive labelling guidance

What the code is for

Food companies use additives for practical reasons. A preservative
may help food last safely for its intended shelf life. An antioxidant
may slow a change in colour or flavour. An emulsifier can help oil and
water stay mixed. A thickener can give a sauce or yoghurt the texture
people expect.

Some additive names look unfamiliar because labels use a functional
class followed by the additive’s name or E number. For example, the FSA
says a label may show “Antioxidant: Ascorbic Acid” or “Antioxidant:
E300”. Food
Standards Agency: PPDS labelling guidance

The number is a label system, not a score for how “natural” or
“chemical” a food is. Vitamin C is ascorbic acid; citric acid occurs
naturally in citrus fruit. Other additives are manufactured. The useful
question is what the ingredient does in that product and whether you
need or want that product in your diet.

A simple label-decoding
table

This is deliberately not a list of “E numbers to avoid”. A list
without product, quantity, context or a personal reason creates more
worry than understanding.

How additives are
regulated in Great Britain

Food additives must be authorised for use in Great Britain. The FSA’s
public register lists authorised food additives, their E numbers, status
and the conditions of use. FSA:
food additive authorisations

That authorisation is linked to a defined use. It is not a blank
permission to add any amount of an ingredient to any food. The register
and its conditions distinguish between additives and food
categories.

For shoppers, the key takeaway is simpler: the ingredient list should
tell you the additive’s functional class and name or E number when it
has a technological function in the finished food. Read the whole
ingredients list and compare products like for like.

What about the warning
labels?

Some additives have additional legal labelling requirements. The FSA
notes that certain sweeteners and colours require specific warning
statements on packaging. Food
Standards Agency: PPDS labelling guidance

Read those statements as written. Do not turn them into a general
claim about every E number, every child or every food. This article
sticks to label wording and official guidance rather than making claims
about children. The label itself and official guidance are the right
source of information.

A calmer way to shop

If you want to eat fewer packaged foods, build that choice around
meals rather than fear of one number. Cook when you can, use tinned and
frozen foods when they make life easier, and compare similar products. A
jar of sauce, a loaf of bread or a flavoured yoghurt can have a place in
an ordinary diet.

If a particular product seems linked with a repeatable digestive
pattern, keep the packet or photograph the label. Note the food, amount
and the rest of the meal. A food diary can be useful for recurring
symptoms, but it cannot prove that one E number is the cause. The NHS
advises seeing a GP if symptoms that seem related to food keep
returning. NHS: Food
intolerance

The practical answer

E numbers are a naming system for authorised food additives, not a
universal red flag. Learn the functional class, read the whole label,
and make food choices that fit your needs rather than chasing a generic
blacklist. For persistent symptoms, take a clear product record to a GP
or dietitian instead of assuming a code on a label has supplied the
answer.

Two useful shopping examples

If you are comparing two tomato sauces, start with the basics: tomato
content, salt, sugar, portion, price and how often you use it. An
additive line may tell you how the sauce achieves its texture or shelf
life, but it is only one part of the product.

For drinks, compare the whole label too. A sweetener or colour can
have its own required wording, but caffeine, alcohol, sugar and serving
size may be more relevant to how a drink fits your day. Reading one code
in isolation creates a false sense of precision.

If an additive is listed because it performs a function in the food,
that information belongs in context. The aim is informed shopping, not
trying to construct a perfect ingredient list from fear.

Related reading: Food Intolerances A–Z.