Allergen labels and “may contain”

What official guidance says

For UK prepacked food, the ingredients list must highlight the 14 allergens regulated by law using a different font, style or background colour. The list includes celery, cereals containing gluten, crustaceans, eggs, fish, lupin, milk, molluscs, mustard, nuts, peanuts, sesame, soya and sulphur dioxide or sulphites above the stated threshold.^[1]

Food Standards Scotland also says that allergen information must be available for prepacked and non-prepacked food and drink. The label remains an important part of a safer choice but it is not personalised medical advice.^[3]

UK: “may contain” is precautionary allergen information

The UK calls “may contain” wording precautionary allergen labelling, or PAL. GOV.UK says it should be used where a business has identified potential allergen cross-contamination that cannot be controlled. It should name the relevant risk, such as “may contain milk”. General wording such as “may contain allergens” should not be used.^[2]

PAL is not a substitute for food hygiene and allergen controls. It also should not appear alongside a free-from claim for the same allergen.^[2]

US: ingredients, Contains statements and the Big 9

For most FDA-regulated packaged foods, the US major allergens are milk, egg, fish, crustacean shellfish, tree nuts, peanuts, wheat, soybeans and sesame. The food source can appear in the ingredients list, in parentheses after an ingredient or in a nearby Contains statement.^{[4] [5]}

If a US Contains statement appears, FDA says it must identify all major allergens used as ingredients. It is not required on every package, so readers still need to check the full ingredients list.^[5]

US: “may contain” is optional wording

US packages may use wording such as “may contain peanuts” or “produced in a facility” where cross-contact is possible. FDA calls these optional advisory statements. They should be truthful and not misleading and must not replace good manufacturing practice.^{[4] [5]}

The absence of optional wording therefore does not answer every cross-contact question. If the label does not provide enough clarity for an allergy-management decision, do not guess. FDA advises contacting the manufacturer or distributor when unsure.^[5]

Why UK and US labels differ

A practical label-reading routine

1. Start with the ingredients list. Look for the allergen itself or a clearly declared source such as `whey (milk)` or `lecithin (soy)`.^[5]
2. Then read any Contains statement. In the US it can make ingredient information easier to spot but it does not replace checking the ingredients list.^[5]
3. Treat named “may contain” wording as a cross-contact warning. It is not simply another way of listing an ingredient.^{[2] [5]}
4. Check the product every time. Recipes, suppliers and labels can change.^[5]
5. Do not make a safety assumption from an unclear label. Follow the individual clinical allergy-management plan and contact the manufacturer where necessary.

Who should be especially cautious

This guide is particularly relevant to someone with a known food allergy, a parent or carer buying food for someone with an allergy and anyone choosing a product whose label has changed. The official sources emphasise avoiding known allergens and checking labels. They do not provide a universal safe threshold for individual consumers.^{[4] [5] [6]}

If someone has a prescribed emergency plan, use that plan rather than relying on a general information article. Serious allergic symptoms need urgent medical attention according to local emergency guidance.

Practical conclusion

Read the ingredients list first. A named allergen means it is part of the food. In the US, a Contains statement can make that information easier to spot but it is not a substitute for reading the ingredients. A “may contain” statement means the manufacturer is warning about possible accidental cross-contact. It is neither proof that an allergen is in every pack nor a reason to assume a product without the wording is free of risk.^{[2] [5]}

If a food is subject to an allergen recall, compare the product name, package details and lot information with the official notice. You can search current recalls on RecallBite. For other label questions, see the guide to best before, use by and best by dates.