Precautionary allergen labelling
“May contain” labelling: when it is justified and what to write
“May contain” is not a disclaimer. Used on everything, it tells an allergic customer nothing and can itself breach food law. Used after a real risk assessment, it is the most useful line on the label.
Checked against the official guidance on 18 September 2026
The FSA's four rules
- Only after a risk assessment, and only for an “unavoidable risk of allergen cross-contamination” (FSA technical guidance) — one you can't remove by segregation or cleaning.
- Never instead of hygiene. Its use “is not a substitute for good food hygiene and safety practices”, and it “could be considered misleading” if there is no real risk.
- Name the allergen. “May contain hazelnut”, “not suitable for someone with a sesame allergy” — never “may contain allergens”.
- Not with “free from” for the same allergen. It can sit next to a vegan label.
Kitchen examples
| Situation | Justified? | What to do |
|---|---|---|
| Chips fried in the same oil as battered fish and scampi | Yes, if you can't give chips their own fryer | Chips: may contain gluten (wheat), fish, crustaceans |
| Brownies cut on the board used for walnut cake | No: that is a cleaning problem | Separate boards or clean between: no warning needed |
| Bakery with sesame-topped rolls, seeds everywhere | Often yes, for unseeded products | Plain rolls: may contain sesame |
| Supplier label says “may contain peanuts” | Pass it on | Carry it into your dish unless your own assessment supersedes it |
| “Just in case” on every dessert | No | Remove it: it removes choice and can mislead |
On the matrix, on the label, on the QR menu
In the matrix builder, “may contain” is its own state (a ring, not a dot), set dish by dish, never suggested automatically: it must come from your assessment. The PDF, the QR menu and the PPDS label print it separately from the ingredients, as a “May contain: …” line.
On a PPDS label, a “may contain” statement is not a legal requirement; the FSA recommends it where the risk is real. On loose food it can be given verbally or on a sign (GOV.UK).
“May contain” questions
Is “may contain” a legal requirement?
No. Precautionary allergen labelling is voluntary. What the law does require is that any information you give is not misleading, which is why the FSA says to use it only where a real risk has been identified.
Can I write “may contain allergens” or “may contain nuts”?
Avoid both. GOV.UK guidance says not to use general statements such as “may contain allergens”, and the FSA asks for the specific food to be named, for example “may contain hazelnut”.
Can a “vegan” dish carry a “may contain milk” warning?
Yes. The FSA's technical guidance says precautionary labelling can be used alongside a vegan label, because vegan is about ingredients, not about allergen cross-contact.
Can I use “may contain” with a “free from” claim?
Not for the same allergen: the FSA says precautionary labelling should not be combined with a “free from” statement for that allergen.
Is there a legal threshold for “may contain”?
Not in UK law. In July 2026 the Codex Alimentarius adopted voluntary international guidelines on precautionary labelling; they have not changed UK law.
Official sources
- Food allergen labelling and information requirements: technical guidance — Food Standards Agency (GOV.UK), published 23 August 2023, revised March 2025.
- Precautionary allergen labelling (PAL) — GOV.UK — food labelling and packaging.
- Labelling guidance for prepacked for direct sale (PPDS) food products — Food Standards Agency (GOV.UK).
- Allergen guidance for food businesses — Food Standards Agency (GOV.UK), updated 17 July 2026.
All sources opened and checked on 18 September 2026. This page is general information, not legal advice.