Allergens on the menu: what a restaurant must tell you

For a proportion of customers this is not a preference but a medical matter. The rules treat it that way and set a minimum that does not depend on the size of the place.

The fourteen groups

Cereals containing gluten, crustaceans, eggs, fish, peanuts, soya, milk, tree nuts, celery, mustard, sesame seeds, sulphur dioxide and sulphites above a threshold, lupin and molluscs. Any dish containing one of them, or a derivative, must declare it. The list comes from European food information rules and is identical across every member state.

Cross contamination

A dish with no gluten containing ingredients may still not be suitable if it was prepared on a shared surface or with shared utensils. The rules require accurate information about composition, and good hygiene practice requires that risk to be controlled. A kitchen that cannot guarantee the absence of traces should say so plainly rather than describe the dish as suitable, because an inaccurate statement creates liability.

What to ask when the allergy is serious

Say so when booking and repeat it when ordering, using the word allergy rather than intolerance if that is the case, because kitchen protocols usually treat them differently. Ask about the preparation surface and utensils. And check the frying oil, which is the critical point: a shared fryer transfers traces of fish, shellfish or gluten to anything that passes through it.

On an island where the season runs from May to October, telling the restaurant at booking gives the kitchen time to organise, which is impossible to improvise with 120 covers in the dining room.

If the information is missing

Failing to provide allergen information is an offence under consumer and food safety rules and can be reported to the competent authority. The complaints book is the first step and every establishment must hold one available. Where a reaction has occurred, keep the receipt, photograph the menu and obtain a medical report: those three elements are what support any subsequent claim.

The numbers put the issue in scale. Coeliac disease affects around 1 per cent of the population, cow's milk protein allergy about 2 per cent of small children, and tree nut allergy persists for life in over 80 per cent of cases. In a dining room of 120 covers that means 2 to 6 people with a restriction that allows no margin, at every service, every day.

A second set of figures: a shared fryer changes oil every 3 to 8 service days and everything fried passes through it, so 1 batch of breaded croquettes can leave traces in the 100 portions that follow. A 40 dish menu against 14 allergens produces 560 cells to fill and maintain, 3 to 6 hours of work the first time and 30 minutes per revision.