By In this article
- What are the 14 allergens, and where do they hide?
- Are peanuts and tree nuts the same allergen?
- Which allergies do children grow out of?
- How are allergens shown on UK food labels?
- What does “may contain” mean?
- What about loose food, restaurants and takeaways?
- What are the signs of an allergic reaction?
- Checking food when there’s no label
- The quick allergen checklist
The 14 major food allergens in the UK are celery, cereals containing gluten, crustaceans, eggs, fish, lupin, milk, molluscs, mustard, peanuts, sesame, soya, sulphur dioxide and sulphites, and tree nuts. UK food law says businesses must tell you when any of them are in the food they sell, whether it’s in a supermarket pack, a bakery counter or a takeaway.
What are the 14 allergens, and where do they hide?
The Food Standards Agency (FSA) describes these 14 as the most potent and common allergens. Some are obvious. Others turn up in places you might not expect.
| Allergen | What it includes, and what to know |
|---|---|
| Celery | Allergy UK says it’s often hidden in many foods |
| Cereals containing gluten | Wheat, rye, barley and oats |
| Crustaceans | Shellfish such as prawns, crab and lobster |
| Eggs | One of the most common allergies in babies and young children |
| Fish | Part of the wider “seafood” group, along with shellfish |
| Lupin | Less familiar, so check ingredients lists for it |
| Milk | Cow’s milk allergy is one of the most common in UK babies and young children |
| Molluscs | Shellfish such as mussels and oysters |
| Mustard | Allergy UK says it can be hidden, so you may not see, taste or smell it |
| Peanuts | A legume that grows underground, not a tree nut |
| Sesame | Sesame seeds, sesame oil and tahini |
| Soya | Soya flour is common in bread, cakes, ready meals, burgers, sausages and baby foods |
| Sulphur dioxide and sulphites | Preservatives that keep colour, flavour and shelf life, listed above 10 parts per million |
| Tree nuts | Almonds, hazelnuts, walnuts, Brazil nuts, cashews, pecans, pistachios and macadamias |
Soya is a good example of how easy it is to miss an allergen. Allergy UK says as many as 60% of manufactured foods contain soya.
Are peanuts and tree nuts the same allergen?
No. Allergy UK points out that peanuts grow underground and belong to the legume family, so they’re listed separately from tree nuts. If you’re not sure which nuts you need to avoid, ask your GP or allergy team.
Which allergies do children grow out of?
Allergy UK says egg and cow’s milk allergies are among the most common in babies and young children. Most children grow out of egg allergy by the time they start school. A small number of people don’t outgrow milk allergy, and Allergy UK says adults who still have it are more likely to have severe reactions.
Tree nut allergies are different. Allergy UK says they tend to last, and people rarely grow out of them, especially after the age of five. If you think your child’s allergy has changed, talk to your GP or allergy team.
How are allergens shown on UK food labels?
On prepacked food, the FSA says any of the 14 allergens must be emphasised in the ingredients list, for example in bold, italics or a different colour. That makes the ingredients list the place to look, not the front of the pack. Our guide on how to read food labels covers the rest of the label.
Since 1 October 2021, food that is prepacked for direct sale (PPDS) must also carry a full ingredients list with the allergens emphasised. The FSA says the label doesn’t replace talking to staff about your allergy.
What does “may contain” mean?
“May contain” or “not suitable for people with a nut allergy” are precautionary labels. They warn that an allergen could be in the food by accident, through cross-contamination during making or packing.
The FSA says there is no specific legal requirement to use these labels, so a food without one isn’t guaranteed to be free of an allergen. If you have a diagnosed allergy, ask your GP or allergy team how to treat “may contain” warnings.
What about loose food, restaurants and takeaways?
You still have the right to know what’s in your food when there’s no label:
- Loose food (bakeries, butchers, delis): the business must give you allergen information. It can be written or spoken, but if it’s spoken, staff must tell you where to find it in writing.
- Restaurants and cafés: allergen information must be on the menu, or there must be a note telling you how to get it.
- Takeaways and delivery: allergen information must be available before you buy and again when the food arrives.
Businesses must give you the information, but they don’t have to make you a different meal. If a business doesn’t provide allergen information, you can report it to the FSA through its “report a food problem” service, which passes it to the local council.
The 14 aren’t the only foods people react to. If your allergen isn’t on the list, the FSA advises checking the label or asking staff.
What are the signs of an allergic reaction?
The NHS lists common symptoms of a food allergy, which can affect several parts of the body at once:
- itchy skin or a raised rash
- swelling of the lips, face and eyes
- sneezing or an itchy, runny or blocked nose
- coughing, wheezing or a hoarse voice
- feeling or being sick, tummy pain or diarrhoea
- feeling dizzy or lightheaded
Symptoms can start straight after eating, or days later. If you think you or your child has a food allergy, see a GP.
When is it an emergency?
Call 999 straight away if lips, mouth, throat or tongue suddenly swell, breathing becomes fast or difficult, the throat feels tight, skin or lips turn blue, grey or pale, or someone becomes confused, drowsy or faints. These can be signs of anaphylaxis.
If you have an adrenaline auto-injector, the NHS says to use it straight away and then call 999, even if the person seems to be getting better. Don’t drive yourself to A&E.
Checking food when there’s no label
Labels and allergen menus do the heavy lifting, but home cooking, buffets and food from friends don’t come with an ingredients list. An app like Dietary Insight can help you think it through: snap a photo of a meal and it flags ingredients that may contain common allergens on your profile. It can’t see everything in a dish, so always read the full label and ask the person who made the food.
The quick allergen checklist
- Learn the 14 allergens, especially the hidden ones like celery, mustard and soya.
- Read the ingredients list every time, even on foods you buy often.
- Ask staff for allergen information when food is loose, made to order or delivered.
- Treat “may contain” warnings the way your GP or allergy team advises.
- Carry your adrenaline auto-injector if you’ve been prescribed one.
Frequently asked questions
What are the 14 major food allergens in the UK?
Celery, cereals containing gluten, crustaceans, eggs, fish, lupin, milk, molluscs, mustard, peanuts, sesame, soya, sulphur dioxide and sulphites, and tree nuts. UK food law requires businesses to tell you when any of these are in their food.
Does 'may contain' mean a food has the allergen in it?
Not necessarily. The Food Standards Agency says 'may contain' labels warn that an allergen could be present by accident, through cross-contamination. If you have a food allergy, ask your GP or allergy team how to treat these warnings.
Do restaurants have to tell me about allergens?
Yes. Restaurants, cafés and takeaways must give you allergen information, either on the menu or by telling you how to get it. They don't have to make you a different meal.
Sources
This article is general information, not medical advice. If you have diabetes, high blood pressure or a food allergy, speak to your GP, diabetes nurse or a registered dietitian before changing your diet or medication. Read our medical disclaimer.