May Contain Warnings: Precautionary Allergen Labelling Explained

Walk down any supermarket aisle or read any café menu in the UK and you'll see phrases like "may contain nuts" or "made in a factory that handles milk". These are known as precautionary allergen labels — and they're widely misunderstood by businesses and customers alike. Here's what the Food Standards Agency (FSA) says about when to use them, when not to, and how to get them right.

Precautionary allergen information — often called "may contain" labelling or PAL — is a voluntary statement used to warn customers about the unintentional presence of one or more of the 14 regulated allergens. It covers risks that remain even after reasonable controls are in place, such as:

• Cross-contact in a shared kitchen or production line
• Ingredients supplied from factories that handle allergens
• Shared equipment, fryers, or storage areas

Unlike the mandatory allergen declaration for ingredients intentionally used in a recipe, precautionary labelling is not a legal requirement — but when a genuine risk exists, the FSA expects businesses to communicate it clearly.

The FSA is clear: precautionary allergen labelling should only be used after a thorough risk assessment shows a real, unavoidable risk of cross-contact that cannot be removed through cleaning, separation, or supplier controls.

Good reasons to use it include:

• A small kitchen where flour dust is genuinely airborne throughout service
• A shared fryer used for breaded (gluten-containing) and non-breaded items
• A supplier who cannot guarantee their ingredient is free from traces of an allergen

Just as important is when not to reach for a "may contain" statement:

• As a blanket disclaimer. Adding "may contain everything" to every product or dish to cover yourself is exactly what the FSA warns against. It dilutes the message, removes meaningful choice for allergic customers, and suggests you haven't assessed your actual risks.
• As a substitute for good allergen management. Precautionary labelling must never replace proper cleaning, separation, staff training, and accurate ingredient records. If the risk can be controlled, control it — don't label it.
• Without a risk assessment. If you haven't looked at where cross-contact could realistically occur, you're guessing — and guessing in either direction puts customers at risk.

The Food Information Regulations 2014 and Natasha's Law (the Food Information (Amendment) (England) Regulations 2019) make allergen declaration mandatory for ingredients deliberately present in food. Precautionary labelling sits outside these requirements — it is voluntary — but the General Food Law still requires that food sold is safe, and the FSA can take action where businesses fail to manage or communicate genuine risks.

In short: you won't be fined for not writing "may contain", but you can absolutely face enforcement if a customer is harmed by a risk you knew about and didn't manage or disclose.

For prepacked and PPDS products, precautionary statements sit alongside the mandatory ingredient list with allergens emphasised. The same rules apply: risk-assess first, be specific, and never use "may contain" as a shortcut around proper controls.

A digital allergen menu makes precautionary information easy to manage. With Allergenius you can add "may contain" notes to individual dishes or products, update them the moment a supplier or process changes, and give customers accurate, dish-specific information via a simple QR code — no reprinting, no guesswork.