Quick answer
Use a “may contain” warning only when a documented risk assessment identifies an unintended allergen risk that remains after appropriate controls. Name the relevant allergen clearly and keep the decision under review. Precautionary allergen information is voluntary, but it must be accurate and must not replace good controls or contradict a free-from claim for the same allergen.
Distinguish an ingredient from a residual transfer risk
An intentionally used allergen belongs in the mandatory ingredient-allergen information. Precautionary allergen labelling, or PAL, addresses possible unintended presence. It should not conceal an incomplete recipe or uncertainty about what was deliberately added.
FSA precautionary-labelling guidance places PAL after assessment of allergen-transfer risk and available risk-management actions. “Made in a kitchen that handles allergens” is not a product-specific assessment by itself.
Assess the evidence before choosing wording
- Identify the allergen and credible route of unintended entry.
- Review supplier information and the actual handling and equipment.
- Apply appropriate prevention, separation and cleaning controls.
- Assess any remaining risk with competent help where needed.
- Record why a warning is or is not appropriate and how it will be reviewed.
Do not invent a universal “safe trace” level or choose a test without understanding its suitability. Sampling, detection limits, recipe distribution and the actual allergen affect what evidence can establish. Specialist assessment may be needed.
Make the warning specific and consistent
Use clear wording identifying the allergen concerned. A general “may contain allergens” statement can be misleading and unhelpful. Specified nuts and cereals need appropriate clarity; “nuts” must not be used to blur a separate peanut risk.
FSA technical guidance distinguishes mandatory declarations, precautionary statements and absence claims. Do not use “free from milk” and “may contain milk” together. Gluten-related claims have a specific legal framework and should be assessed separately.
Handle supplier precautionary information
The FSA advises that supplier precautionary information should reach the final consumer unless the food business’s own risk assessment supersedes it. Do not silently delete a supplier warning because the ingredient is used in a small quantity or because a competing product has no warning.
Illustrative example: a bakery receives flour with a changed precautionary statement. Check the reason, current specification and relevance to the finished product. Record the assessment and any information change before use; merely copying or removing the statement without understanding it is not an adequate decision.
Review the decision and explain it to staff
Review PAL when suppliers, equipment, recipes, cleaning arrangements or credible incident information change. Keep the decision connected to actual production. A warning added years ago should not become permanent without reassessment; an absence of complaints does not prove absence of risk.
Make sure staff can explain the distinction between an ingredient declaration and a precautionary warning without assuring customers that a stated risk can be ignored. Vegan or vegetarian descriptions can coexist with appropriate PAL because those descriptions communicate different information from an allergen-free claim.
Next steps
- Assess the specific transfer risk and prevention measures.
- Obtain competent evidence for any residual-risk decision.
- Use clear, consistent wording and retain the rationale.
- Review changes and train staff to explain the information accurately.
Read the official practical guidance — Use the current source alongside the procedures for your own business.