UK food law requires every food business to provide clear information about 14 specific allergens. Whether you run a restaurant, café, pub, hotel kitchen or food truck, understanding these allergens — what they are, where they hide, and how to communicate them — is both a legal requirement and a basic duty of care to your customers.
This guide covers every one of the 14 allergens recognised under UK food law, explains where they commonly appear in food, and tells you what your legal responsibilities are.
Why 14 allergens?
The UK's list of 14 allergens — inherited from EU Food Information Regulations and retained in UK law following Brexit — represents the foods most commonly responsible for serious allergic reactions. These are not the only foods that can cause allergies, but they are the ones that food businesses are legally required to identify and communicate.
An allergic reaction occurs when the immune system mistakenly treats a food protein as a threat. Reactions range from mild discomfort to anaphylaxis — a severe, life-threatening reaction that requires emergency treatment. For the approximately 2 million people in the UK living with a diagnosed food allergy, knowing exactly what is in their food is not a preference. It is a matter of safety.
The 14 allergens
1. Cereals containing gluten
This includes wheat, rye, barley, oats and spelt, and any products derived from them. Gluten is the protein found in these grains and is responsible for reactions in people with coeliac disease and wheat allergy.
Where it commonly appears: Bread, pasta, flour, cakes, biscuits, pastry, beer, sauces thickened with flour, coatings and breadcrumbs, soy sauce (which typically contains wheat).
Watch out for: "Gluten-free" oats exist but standard oats are frequently contaminated with wheat during processing and must be declared.
2. Crustaceans
Includes prawns, crabs, lobster, crayfish and langoustines. The allergenic proteins in crustaceans can cause severe reactions, and crustacean allergy is one of the most common triggers for anaphylaxis.
Where it commonly appears: Seafood dishes, prawn crackers, fish stocks, paella, bisques, some Asian sauces and pastes, shellfish-based garnishes.
Watch out for: Cross-contamination in kitchens where crustaceans and non-crustacean dishes are prepared near each other.
3. Eggs
Egg allergy is particularly common in children, though many outgrow it. The allergen is found in both the white and the yolk.
Where it commonly appears: Cakes, pastries, mayonnaise, hollandaise, quiche, pasta (fresh egg pasta), meringues, some ice creams, glazes, battered foods.
Watch out for: Many sauces and dressings contain egg as an emulsifier without it being obvious from the dish name.
4. Fish
Fish allergy is distinct from crustacean and mollusc allergy — a guest allergic to fish may not be allergic to shellfish, and vice versa. The allergen is a protein called parvalbumin, found across most fish species.
Where it commonly appears: Obvious fish dishes, but also Worcestershire sauce, Caesar dressing, fish stocks, some Asian sauces (fish sauce, oyster sauce), pizza toppings.
Watch out for: Fish sauce is a common hidden ingredient in Thai, Vietnamese and other cuisines.
5. Peanuts
Peanuts are technically a legume, not a tree nut, but are listed separately because peanut allergy is one of the most prevalent and potentially severe food allergies. It affects around 2% of children in the UK.
Where it commonly appears: Peanut butter, satay sauces, some curries, biscuits, chocolates, cereal bars, Asian dishes, some salad dressings.
Watch out for: Cross-contamination is a major risk. Peanuts are processed and handled widely, so even dishes that don't contain peanuts can be contaminated if kitchen hygiene is not carefully managed.
6. Soybeans (soya)
Soya is widely used as an ingredient in processed foods and is common in Asian cuisine. Soya allergy is particularly prevalent in infants and young children.
Where it commonly appears: Tofu, edamame, miso, tempeh, soy sauce, many meat alternatives, some breads, protein bars, infant formula, chocolate.
Watch out for: Soya-derived ingredients appear under many names on labels — soya flour, soya protein, soya isolate, textured vegetable protein (TVP).
7. Milk (dairy)
Milk allergy — where the immune system reacts to milk proteins — is different from lactose intolerance, which is a digestive issue rather than an immune response. Both require careful menu management but for different reasons.
Where it commonly appears: Obvious dairy products (butter, cream, cheese, yoghurt), but also many processed foods, some crisps and snacks, chocolate, margarines, battered coatings, some breads.
Watch out for: Milk derivatives like casein, whey and lactalbumin appear in many unexpected products.
8. Tree nuts
This category covers a wide range of nuts: almonds, hazelnuts, walnuts, cashews, pecans, Brazil nuts, pistachios, macadamia nuts and Queensland nuts. Tree nut allergy is among the most common causes of anaphylaxis and is often lifelong.
Where it commonly appears: Confectionery, pastries, curries, pestos (pine nuts are also a tree nut), desserts, marzipan (almonds), praline, some oils and butters.
Watch out for: Cross-contamination between different nut types is common in production and in kitchens. A guest allergic to one tree nut may react to others.
9. Celery
Celery allergy is more common in mainland Europe than in the UK but is significant enough to be included on the list. The allergen is present in all parts of the plant — stalk, leaves, seeds and root (celeriac).
Where it commonly appears: Soups, stocks, salads, Bloody Mary cocktails, some spice mixes, celeriac dishes, celery salt.
Watch out for: Celery seeds and celery salt are used as flavouring and may not be obvious to kitchen staff or guests.
10. Mustard
Mustard allergy can be triggered by the seed, the leaf or the oil. Reactions can be severe. This allergen is one that kitchen teams sometimes overlook.
Where it commonly appears: Condiments and sauces (obviously), but also salad dressings, marinades, some curries (mustard seeds), coleslaw, pickles, some bread products, spice mixes.
Watch out for: Mustard is a common ingredient in spice blends and rubs used in cooking — it may not be listed as "mustard" in a recipe.
11. Sesame
Sesame allergy has risen significantly in recent years and can cause severe reactions. Both sesame seeds and sesame oil are allergenic.
Where it commonly appears: Hummus (tahini), bread rolls and bagels (sesame seeds on top), Asian cuisine, halva, some salad dressings, sesame oil used in cooking.
Watch out for: Sesame oil used as a flavouring — even a small amount can trigger a reaction in severely allergic individuals.
12. Sulphur dioxide and sulphites
Sulphites are preservatives used widely in food and drink. At concentrations above 10mg/kg or 10mg/litre (expressed as SO₂), they must be declared. They can trigger asthma symptoms and other reactions, particularly in people with existing respiratory conditions.
Where it commonly appears: Wine and beer, dried fruits, soft drinks, some processed meats, vinegar, pickled foods, some ready-made sauces and condiments.
Watch out for: The threshold rule — sulphites only need declaring above a certain concentration, but in practice it's safer to declare them where present.
13. Lupin
Lupin is a flowering plant whose seeds are increasingly used as a flour substitute, particularly in gluten-free products. It is closely related to peanuts, and people with peanut allergy may also react to lupin.
Where it commonly appears: Some gluten-free bread and pasta, certain flour mixes, lupin-based protein products, some pastries.
Watch out for: Lupin is a relatively recent addition to everyday ingredients and kitchen teams may be less aware of it than more established allergens.
14. Molluscs
Molluscs are a broad category that includes mussels, oysters, squid, scallops, clams, octopus, snails and abalone. Mollusc allergy is separate from fish and crustacean allergy.
Where it commonly appears: Seafood dishes, paella, some Asian soups and broths, oyster sauce.
Watch out for: Oyster sauce — a common ingredient in stir-fries and Asian cooking — contains molluscs and must be declared.
Your legal responsibilities
Under the UK Food Information Regulations, food businesses must:
- Provide information on all 14 allergens when present in any food served
- Make this information available before the customer orders
- Keep allergen information accurate and up to date at all times
- Not misrepresent the allergen content of food
The Food Standards Agency's 2025 guidance specifically encourages businesses to display allergen information directly on menus rather than relying solely on verbal communication from staff — significantly raising the practical standard expected of food businesses.
Natasha's Law, in force since October 2021, adds a further requirement: all food pre-packaged for direct sale (PPDS) must carry a full ingredient and allergen label.
The problem with manual allergen management
Tracking 14 allergens across a full menu — and keeping that information accurate as recipes change, suppliers switch and seasonal dishes come and go — is genuinely difficult to do manually. Paper allergen matrices go out of date. Staff knowledge varies. Verbal communication introduces risk.
This is why allergen management software exists. Allergenius lets you assign all 14 allergens to every dish on your menu, keep that information updated in real time, and make it accessible to every guest via a QR code — on any device, without any app to download.
See how Allergenius manages all 14 allergens →
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