14 Allergens: A Guide for Food Workers

• The 14 allergens are: celery, cereals containing gluten (such as wheat, barley, rye, oats), crustaceans, eggs, fish, lupin, milk, molluscs, mustard, peanuts, sesame, soya, sulphur dioxide/sulphites and tree nuts.
• These allergens can appear in obvious forms (like prawns, bread or milk) but are often hidden in sauces, coatings, flavourings, spice mixes or processed foods.
• Cross-contact is a major risk in shared kitchens, restaurants and bakeries handling multiple allergens.

The 14 “major” allergens are a group of ingredients found to be responsible for the majority of severe allergic reactions.

Each has been linked to a high rate of reported allergic reactions and a significant risk of anaphylaxis (a severe allergic reaction that happens very quickly and can be life-threatening).

Importantly, these ingredients also appear across a wide range of products, increasing the likelihood of accidental exposure or cross-contact (when allergen-free food picks up allergens after coming into contact with other foods, equipment, or surfaces). Cross-contact is a major risk – even a trace of allergens can make food unsafe to eat for sensitive individuals.

To help you recognise and manage them, we’ve listed the 14 allergens below, with examples of where they are most often found.

Celery is widely used as a base ingredient and often hidden in recipes. It became mandatory to declare it on food labels in 2014.

Where it is found: Soups, stews, stocks, sauces, spice mixes, salads, condiments, smoothies, ready meals, celeriac and celery salt.

What to watch for: Celery can still trigger reactions even when dried or cooked. Always check labels carefully, especially with spice mixes, bouillons and prepared foods.

Cereals that contain gluten, including wheat, barley, rye and oats, are widely used in everyday foods and are among the most difficult allergens to manage safely.

Gluten can cause reactions that range from mild discomfort to severe symptoms. Breathing in flour dust can also lead to asthma-like symptoms, so extra care is needed when preparing food.

Where it is found: Bread, pasta, breakfast cereals, cakes, biscuits, soups, sauces, gravies, batters, coatings and processed meats.

What to watch for: Cereals containing gluten are often used as thickeners or fillers, so they may not always be easy to spot. Always check ingredient labels carefully.

Reactions to egg are usually caused by proteins in the white, though the yolk can also trigger symptoms. Some people outgrow egg allergy in childhood, while for others it can persist into later life.

Where it is found: Cakes, pastries, biscuits, sauces, mayonnaise, salad dressings, glazes, batters, pasta and processed foods.

What to watch for: Eggs appear in many forms, including dried or powdered egg used in manufacturing.

Fish is a common lifelong allergen and can cause reactions ranging from mild skin symptoms to severe anaphylaxis. Fish proteins are heat-stable, which means cooking does not remove the allergen. Any food containing fish remains unsafe for people with a fish allergy, even after baking, frying, or boiling.

Where it is found: Fresh or frozen fish, tinned fish, fish sauces (e.g. Worcestershire, oyster, fish sauce), Caesar dressings, pizza toppings, ready meals, relishes and dips like taramasalata.

What to watch for: Fish protein can spread through steam or oil during cooking and cause cross-contact in shared fryers, counters and takeaways.

Crustaceans, such as prawns, crab, lobster and crayfish, are a major allergen and can trigger reactions even in very small amounts.

Where it is found: Prawns, scampi, crab dishes, lobster, shrimp, prawn crackers, Asian-style stir-fries, paella, seafood pastes and sauces like oyster sauce.

What to watch for: Cross-contact is a high risk in shared fryers, mixed seafood dishes or where equipment is reused without thorough cleaning.

Molluscs include mussels, clams, oysters, squid and scallops are another major allergen with the potential to cause severe reactions. Because they are used in sauces, stocks and mixed seafood dishes, they may not always be obvious to customers, creating a higher risk of accidental exposure.

Where it is found: Shellfish platters, seafood chowder, bouillabaisse, paella, stir-fries, battered or crumbed seafood, pizza toppings and sauces such as oyster or clam sauce.

What to watch for: Molluscs are easily hidden in flavourings and broths, and cross-contact is common at fish counters or in kitchens handling multiple types of seafood. Non-food products such as biodegradable straws or cosmetics may also contain derivatives from molluscs.

Milk allergy is most commonly seen in babies and young children, many of whom outgrow the allergy by school age. However, the condition can last into adulthood and may lead to severe reactions, including anaphylaxis.

Where it is found: Milk, cheese, butter, cream, yoghurt, desserts, chocolate, baked goods, sauces, soups and processed foods.

What to watch for: Milk proteins cannot be removed by heat, so all dairy-based ingredients remain a risk. Clear labelling and strict separation are essential to protect customers with milk allergy.

Mustard is often added in small amounts to boost flavour or act as a thickener. You cannot rely on sight, taste or smell to identify it, so accurate labelling and extra care in preparation are essential.

Where it is found: Table mustards such as English, Dijon, wholegrain and sweet varieties; pickles and chutneys; sauces including curry and barbecue sauce; salad dressings, mayonnaise, marinades, deli meats, sausages, stock cubes, baby foods, flavoured oils and mustard greens.

What to watch for: Mustard can still cause a reaction when it’s ground, powdered or processed. Always check labels carefully, especially for prepared or imported foods where labelling may not be clear.

Peanut allergy is one of the most common and serious food allergies, affecting around 1 in 50 children in the UK. It also commonly continues into adulthood, with only a small number of people outgrowing it. In rare cases, the allergy can even develop later in life.

Reactions can be triggered by even the smallest trace of peanut protein and may cause severe anaphylaxis.

Where it is found: Peanut butter, snack bars, confectionery, cakes, biscuits, sauces such as satay, Asian and Middle Eastern dishes, desserts, ice creams, marinades, curries and vegetarian protein substitutes.

What to watch for: Cross-contact is a major risk in kitchens using peanut oil, shared fryers or utensils. Labels must always be checked carefully, particularly on imported products.

Sesame allergy can develop at any age. Some children may tolerate whole seeds on bread, but when the seeds are crushed in foods like hummus or tahini, the proteins are released and can trigger severe reactions. Sesame oil is equally risky, as it is usually cold-pressed and retains these allergenic proteins.

Where it is found: Bakery products such as bread, bagels, crackers, biscuits and muesli; Middle Eastern foods including hummus, tahini and halvah; sauces, dips, chutneys, processed meats, samosas, veggie burgers and even confectionery. Sesame may also appear in herbal drinks, often listed as Sesamum indicum.

What to watch for: Because sesame allergy is as serious as peanut allergy but less widely recognised, you must carefully check labels and confirm ingredients with suppliers. Cross-contact is common in unwrapped bread products or patisserie counters. Reused cooking oils in catering present an additional risk.

Tree nut allergy affects around 2% of children and 0.5% of adults in the UK. It usually develops early in life and rarely disappears with age. Reactions occur when the immune system identifies proteins in nuts as harmful, and many people react to more than one type because the proteins are similar.

Where it is found: Almonds, cashews, walnuts, hazelnuts, pistachios, pecans, Brazil nuts and macadamias. Tree nuts are commonly used in confectionery, cakes, pastries, cereals, sauces, spreads, nut butters, oils and dairy alternatives.

What to watch for: Tree nuts can be ground, pressed into oils or blended into processed foods, making them difficult to detect. Cross-contact is a frequent risk in bakeries, cafes and restaurants handling mixed nuts.

Soya is one of the most common food allergens because it is widely used in processed foods. It comes from the soybean and can appear under different names on ingredient lists.

Where it is found: Soya milk, tofu, tempeh, miso, soy sauce, edamame, soya flour, textured vegetable protein, baked goods, sauces, soups, processed meats, confectionery and infant formula. Soya lecithin (E322) is often used in chocolate and spreads.

What to watch for: Soya may be labelled as vegetable protein, hydrolysed vegetable protein or textured vegetable protein. Refined soya oil usually does not cause reactions, but cold-pressed oil can.

Lupin is one of the lesser-known allergens. It comes from the seeds of the lupin plant, which are ground into flour and used in baked goods and some gluten-free or vegan products. It’s not widely used in the UK, but can be a common ingredient in imported products.

Where it is found: Pastries, pies, pancakes, waffles, biscuits, pasta, pizza bases, processed meats, breadcrumb coatings, deep-fried vegetables like onion rings, vegan alternatives and some gluten-free foods. It may also appear in breads at continental markets and health food shops.

What to watch for: Lupin can be hidden as flour in imported or specialist goods. Always check labels carefully and be alert when handling products from Europe. Because lupin is part of the legume family, some people with peanut allergy may also react, so check allergen risks with customers where relevant.

Sulphites are preservatives that help prevent food and drink from spoiling. They are not a common cause of true allergy, but they can trigger asthma-like symptoms in some people with asthma or a diagnosed sulphite sensitivity.

Where it is found: Preservatives in dried fruit, wine, beer, cider, bottled lemon and lime juice, soft drinks, pickled foods, sauces, guacamole, tinned coconut milk, pre-cut potatoes, prawns and some processed meats.

What to watch for: Sulphites must be declared on labels when present at levels above 10mg/kg or 10mg/l. They may appear under additive codes E220–E228.

In the UK, food business operators (FBOs) are primarily responsible for food safety and allergen information.

The most significant laws they must comply with are the  Food Safety Act 1990 and the Food Information Regulations 2014. Key requirements include:

• Food businesses must take all reasonable precautions to prevent allergen cross-contact during the storage, preparation, handling and service of food.
• For prepacked food, allergens must be listed in the ingredients and emphasised, usually in bold.
• For non-prepacked food sold in restaurants, cafés, or takeaways, allergen information must be available at the point of sale. It can be provided in writing or orally if customers are clearly directed on how to ask.
• Since October 2021, all food prepacked for direct sale (PPDS) must display the food name plus a full ingredients list with allergens highlighted (Natasha’s Law).

While the legal duty rests with the FBO, frontline staff have a critical part to play. They handle ingredients, prepare meals and answer customer questions. FBOs must ensure that all food workers have received suitable instruction, training or supervision on handling allergens.

Train your staff with online Food Allergen Training. It’s relevant for anyone who prepares, handles or serves food, covering:

• The risks linked to the 14 regulated allergens
• Legal duties and labelling rules businesses must follow
• How food safety systems help prevent cross-contact

Enrol your staff today and give them the knowledge to manage allergens safely.