UK food law requires that 14 major allergens be declared whenever they are used as ingredients in food. For pre-packed and PPDS (pre-packed for direct sale) food, these allergens must be emphasised in the ingredients list — typically in bold — so that allergy sufferers can identify them at a glance.
This is not optional. Failure to declare allergens correctly is a criminal offence under the Food Information Regulations 2014, and the consequences of an undeclared allergen reaching an allergic customer can be fatal.
Here is the complete list.
1. Cereals Containing Gluten
Includes: Wheat, rye, barley, oats, spelt, kamut, and their hybridised strains.
Gluten is a protein found in these cereals and products derived from them. This is one of the most widely encountered allergens in commercial kitchens — it appears in bread, pasta, pastry, batter, breadcrumbs, sauces thickened with flour, soy sauce, and many processed ingredients.
Watch out for: Oats are naturally gluten-free but are frequently contaminated during processing. Unless certified gluten-free oats are used, they must be declared.
2. Crustaceans
Includes: Prawns, shrimp, crabs, lobster, crayfish, langoustine.
Crustacean allergy tends to be severe, with a high likelihood of anaphylaxis. Cross-contamination during preparation is a significant risk — shared fryers, chopping boards, and utensils can transfer crustacean proteins to other dishes.
3. Eggs
Includes: Eggs from any bird species, and products derived from them (albumin, lysozyme, mayonnaise, meringue, some glazes).
Egg is found in a wide range of prepared foods including pasta, cakes, quiches, sauces, and coatings. Egg white (albumin) is sometimes used as a fining agent in wine and beer.
4. Fish
Includes: All species of fish, and products derived from them (fish sauce, Worcestershire sauce, some Caesar dressings, fish stock).
Fish allergy is distinct from shellfish allergy — an allergy to one does not necessarily mean an allergy to the other. Fish-derived ingredients appear in many products where they are not obvious, including some Asian sauces, certain flavour enhancers, and some vitamin supplements.
5. Peanuts
Includes: Peanuts (groundnuts) and products derived from them (peanut oil, groundnut oil, peanut butter, peanut flour).
Peanuts are technically legumes, not tree nuts, but they are one of the most common causes of severe allergic reactions. Peanut allergy often presents early in childhood and can be lifelong. Cross-contamination is a serious concern in kitchens that handle both peanuts and peanut-free ingredients.
6. Soybeans
Includes: Soybeans and products derived from them (tofu, tempeh, soy sauce, miso, edamame, soy milk, soy flour).
Soy is widespread in processed foods, Asian cuisines, and vegetarian and vegan products. It appears in many ingredient lists under names such as soya, soy protein, textured vegetable protein (TVP), and hydrolysed soy protein.
7. Milk
Includes: Milk from any mammal (cow, goat, sheep, buffalo), and all dairy products (butter, cream, cheese, yogurt, casein, whey, lactose).
Milk allergy is distinct from lactose intolerance — a milk allergy is an immune response to milk proteins (casein and whey), while lactose intolerance is a digestive issue. Milk proteins appear in many processed foods, marinades, and coatings. Lactose is used as a carrier in some medications and food additives.
8. Nuts
Includes: Almonds, hazelnuts, walnuts, cashews, pecan nuts, Brazil nuts, pistachio nuts, macadamia nuts (Queensland nuts).
This category covers tree nuts only — peanuts are listed separately. Each nut is technically a distinct allergen, but UK law groups them together under this category for labelling purposes. Nut oils, nut flours, marzipan, praline, and many confectionery products contain nuts.
9. Celery
Includes: Celery stalks, leaves, seeds, and celeriac (celery root). Also celery salt and celery-based flavourings.
Celery is commonly found in soups, stocks, salads, spice mixes, and some meat products. Celery seed is used as a flavouring in a wide range of products and may not be immediately obvious from the product name.
10. Mustard
Includes: Mustard plant leaves, seeds, and products derived from them (mustard powder, mustard oil, mustard paste, prepared mustard).
Mustard appears in many condiments, salad dressings, marinades, spice mixes, and processed meat products. It is often present in curry powders and some bread products.
11. Sesame
Includes: Sesame seeds and products derived from them (tahini, sesame oil, sesame flour).
Sesame is the allergen at the centre of Natasha’s Law. It is used extensively in Middle Eastern, Asian, and bakery products and can be difficult to detect visually. Sesame oil is used in many Asian dishes and is not destroyed by cooking.
12. Sulphur Dioxide and Sulphites
Includes: Sulphur dioxide (SO₂) and sulphite salts (sodium sulphite, potassium bisulphite, sodium metabisulphite, etc.).
This allergen must be declared when present at concentrations of more than 10mg/kg or 10mg/litre in the finished product. Sulphites are used as preservatives in wine, beer, dried fruit, processed meats, and some condiments. They can trigger asthma symptoms in sensitive individuals.
13. Lupin
Includes: Lupin seeds and flour (lupin flour is sometimes used as a wheat flour substitute in gluten-free products).
Lupin is less well-known than other allergens but cross-reactivity with peanut allergy is documented. Lupin flour appears in some bread, pasta, pastry, and pancake mixes — particularly those marketed as gluten-free or high-protein alternatives.
14. Molluscs
Includes: Clams, mussels, oysters, scallops, squid (calamari), octopus, snails, abalone.
Mollusc allergy is distinct from crustacean allergy. Molluscs are used in many seafood dishes, and oyster sauce and squid ink are common cooking ingredients that must be declared.
How Allergens Must Be Presented on Labels
Simply listing allergens is not enough. UK law requires that allergens be emphasised relative to the rest of the ingredients list. Accepted methods include:
- Bold text (most common)
- Underlined text
- Capitalised text
- Contrasting colour
The allergen must be emphasised every time it appears in the ingredients list, not just the first occurrence.
What About “May Contain” Warnings?
“May contain” or “produced in a facility that handles” statements are voluntary under UK law — they are not a legal requirement. However, they are recommended when genuine cross-contamination risk exists during production.
Importantly, a “may contain” warning does not replace the legal requirement to declare allergens that are actual ingredients. If sesame is an ingredient, it must be declared in the ingredients list, not just mentioned in a may-contain statement.
Keeping Labels Accurate
The most common labelling failure is not a missing allergen on day one — it is an allergen that is added to a recipe later and never reflected on the label. Every time a recipe changes, even a minor substitution, every affected label must be updated.
For kitchens managing multiple products across multiple locations, this is a significant operational challenge. Purpose-built labelling systems centralise the product catalogue so that a single update propagates to every label printed across every device.
LabelFood prints fully compliant allergen labels in seconds. All 14 allergens are automatically highlighted on every label, every time. See how it works →
