For the estimated 2 million people in the UK living with a diagnosed food allergy — and many more managing intolerances — every food purchase involves a careful label check. A scanner app can make that process faster and more thorough, catching allergens you might miss when reading tiny print under supermarket lighting.
UK food labelling regulations, overseen by the Food Standards Agency (FSA), require manufacturers to clearly declare the presence of 14 major allergens in all pre-packed food. These allergens must be emphasised in the ingredients list, typically in bold text.
| Allergen | Common sources |
|---|---|
| Celery | Soups, stocks, salads, some spice mixes |
| Cereals containing gluten | Wheat, rye, barley, oats (bread, pasta, biscuits, sauces) |
| Crustaceans | Prawns, crab, lobster, crayfish |
| Eggs | Cakes, mayonnaise, pasta, quiche, some sauces |
| Fish | Fish fingers, pizza toppings, Worcestershire sauce, some dressings |
| Lupin | Some breads, pastries, and pasta (more common in continental products) |
| Milk | Butter, cheese, cream, yoghurt, chocolate, many processed foods |
| Molluscs | Mussels, oysters, squid, snails |
| Mustard | Salad dressings, marinades, curries, sauces, soups |
| Peanuts | Peanut butter, satay sauces, some cereals and snacks |
| Sesame | Bread, hummus, tahini, some Asian dishes |
| Soybeans | Tofu, soy sauce, many processed foods, vegetable oil blends |
| Sulphur dioxide & sulphites | Dried fruit, wine, beer, some soft drinks, sausages |
| Tree nuts | Almonds, hazelnuts, walnuts, cashews, pecans, pistachios, Brazil nuts |
These regulations apply to food sold in England, Wales, Scotland, and Northern Ireland. The FSA provides detailed guidance on its website for both consumers and food businesses.
Natasha's Law came into effect on 1 October 2021, following the tragic death of 15-year-old Natasha Ednan-Laperouse, who suffered a fatal allergic reaction to sesame in a Pret A Manger baguette that did not have an ingredients label.
The law requires all food that is prepacked for direct sale (PPDS) to carry a full ingredients list with allergens emphasised. PPDS food is food that is packaged at the same location where it is sold, before a customer selects or orders it. Examples include:
Before Natasha's Law, these products only needed to display the product name — they did not require an ingredients list. The change has significantly improved allergen visibility for foods that were previously a major blind spot.
Scanner apps are a valuable tool for allergen checking, but the FSA recommends that people with severe food allergies (anaphylaxis risk) always read the physical label as their final check. Product formulations can change, and database updates may lag behind recipe changes. Use scanning as your first check, physical label reading as your safety net.
When you scan a food barcode with an allergen-aware app like NutraSafe, several checks happen simultaneously:
The app checks the product's ingredient list against the 14 major allergens and highlights any that are present. This mirrors what is shown on the physical label, but presented clearly on your phone screen.
This is where scanner apps add real value. Many allergens appear under technical or alternative names that are not immediately obvious:
A good scanner app maintains a database that maps all these alternative names to their allergen sources, so a single scan catches things you might miss when reading the label manually.
Where available in the database, scanner apps also display precautionary allergen labelling ("may contain traces of..."). These warnings indicate a risk of cross-contamination during manufacturing. It is worth noting that "may contain" labelling is voluntary in the UK — manufacturers are not legally required to include it, so its absence does not guarantee the product is free from cross-contamination.
Understanding the limits of labelling is important for anyone with severe allergies:
Many food products are manufactured in facilities that also handle allergens. A product might not contain peanuts as an ingredient but could have traces due to shared production lines. The "may contain" warning is the manufacturer's way of flagging this risk, but its use is inconsistent across the industry.
The FSA has been working on improving precautionary allergen labelling standards. Their guidance encourages manufacturers to use "may contain" warnings only when there is a genuine, assessed risk of cross-contamination, rather than as a blanket disclaimer. However, enforcement is still developing, and practices vary between manufacturers.
For severe allergies, consider:
Here is a practical approach to using a scanner app for allergen-safe shopping:
Over time, you will build a list of products you know are safe. Most scanner apps maintain a history, so you can quickly reference past scans rather than re-checking every visit. This is particularly useful for weekly staples where the formulation rarely changes.
While barcode scanning works for packaged food, eating out requires a different approach. Under UK law (from the EU Food Information for Consumers Regulation, retained in UK law), restaurants, cafes, and takeaways must be able to provide allergen information for every dish on their menu. Always ask, and consider using NutraSafe's food diary to log what you eat and track any reactions.
Some of the most frequently missed allergens hide in unexpected products:
Dairy can appear in crisps (as milk powder flavouring), bread (as whey), processed meats (as caseinates), and even some wines (fined with casein). It is one of the most pervasive allergens in the UK food supply.
Soy lecithin (E322) is used as an emulsifier in chocolate, baked goods, margarine, and many processed foods. Soy protein also appears in some meat alternatives, sauces, and ready meals. Given soy's prevalence, a scanner app that flags it automatically saves considerable time.
Gluten-containing cereals appear in soy sauce (wheat-based), many sauces and gravies (flour as thickener), some crisps (malt vinegar flavouring), communion wafers, and beer. For people with coeliac disease, even small amounts matter.
Sesame has become increasingly common in UK food products and is now recognised as a significant allergen. It appears in bread, hummus, tahini, some Asian sauces, and as a seed topping on buns and rolls. Its addition to the 14 major allergens reflects the growing number of sesame allergies in the UK.
NutraSafe flags all 14 major allergens, identifies hidden allergen names, and lets you set personalised allergen profiles. One scan gives you the full picture.
Download NutraSafe FreeUnder UK food law (overseen by the FSA), the 14 major allergens that must be declared on food labels are: celery, cereals containing gluten (wheat, rye, barley, oats), crustaceans, eggs, fish, lupin, milk, molluscs, mustard, peanuts, sesame, soybeans, sulphur dioxide and sulphites (above 10mg/kg), and tree nuts (almonds, hazelnuts, walnuts, cashews, pecans, Brazil nuts, pistachios, macadamia nuts).
Natasha's Law (the UK Allergen Labelling for Prepacked for Direct Sale food regulation) came into effect on 1 October 2021. It requires all food that is prepacked for direct sale (PPDS) — such as sandwiches made in a shop and wrapped before a customer selects them — to carry a full ingredients list with allergens emphasised. This law was introduced following the death of Natasha Ednan-Laperouse, who had a fatal allergic reaction to a Pret A Manger baguette.
Scanner apps can display "may contain" (precautionary allergen labelling) information when it is recorded in their database. However, "may contain" warnings are voluntary in the UK — manufacturers are not legally required to include them. This means the absence of a "may contain" warning does not guarantee zero cross-contamination risk. Always use scanner apps as an additional tool alongside reading the physical label, especially for severe allergies.
Good allergen scanner apps maintain databases that map ingredient names to their allergen sources. For example, casein and whey are flagged as dairy, lecithin (E322) is flagged as potentially from soy or eggs, and semolina is flagged as a gluten-containing cereal. NutraSafe identifies these hidden allergens automatically when you scan a barcode, so you do not need to memorise every technical ingredient name.
No. Scanner apps are an excellent first-check tool and catch allergens quickly, but they should complement — not replace — reading the physical label. Product recipes can change, and there may be a delay before databases are updated. For life-threatening allergies (anaphylaxis risk), always read the physical label as the final check. The FSA recommends that people with food allergies always read the label, even for products they have bought before.
Last updated: February 2026