A dish may not contain an allergen in its recipe and yet still contain it because it got mixed in by accident. This is called cross-contact (or allergen cross-contamination). For a person with an allergy or coeliac disease, it can be enough to cause a reaction.
How it happens
- Shared utensils: the same spoon for a cream sauce and a "dairy-free" one; the same knife for bread and for cheese.
- Surfaces and boards not cleaned properly between one preparation and another.
- Shared fryer oil: the oil used to fry croquettes or battered food contains wheat flour and egg, and passes them on to "gluten-free" chips.
- Hands and gloves that touch one allergen and then another food.
- Shared griddle or grill: residues of milk, bread or shellfish.
- Airborne particles: flour, ground nuts, sesame.
- Splashes: stocks containing shellfish or celery.
- Poor storage order: a product containing peanuts above another that is uncovered.
- Shared cooking water: gluten pasta and gluten-free pasta in the same pot.
Basic measures
- Wash your hands and change gloves before preparing a dish for a person with an allergy.
- Clean utensils, boards and containers, kept for that purpose. Use the ones your workplace reserves for this, or wash them thoroughly with detergent and hot water before use.
- Clean the work surface first. Wiping it with a dry cloth is not enough.
- Prepare the dish without the allergen first and the rest afterwards, if you have to work with both.
- Clean oil or a separate fryer if the dish must be gluten-free or free from other allergens.
- Pasta, rice or cooking water in separate containers.
- Cover and label all containers, including those for dry ingredients.
- Store the most dangerous allergens in separate areas and below products without allergens, so that nothing falls onto them.
- Avoid using the same griddle or grill without cleaning it first.
- Beware of flour in the air: if flour is used in your kitchen, remember that it can settle on other dishes.
Cleaning must be effective
To remove an allergen, disinfecting is not enough: disinfectant does not remove proteins. You must clean with detergent and water and rinse well. Then disinfect if your procedure requires it. Since 2021, Regulation (EC) 852/2004 (amended by Regulation (EU) 2021/382) has prohibited using equipment, means of transport and containers that have held an allergen for food that is free from it, unless they have been cleaned and it has been checked, at the very least, that no visible residue remains.
The "special" dish
If a customer mentions an allergy, some workplaces use a coloured tray or card to mark the order so that the whole team can see it. It can also be noted on the order slip. Kitchen and floor staff must talk to each other: the waiter passes on the allergy, the cook checks the recipe and whoever serves confirms that the dish is the right one.
"Traces"
You will see "may contain traces of…" on some packaging. That warning is voluntary and does not replace good practice. In your kitchen you cannot warn of "possible traces" to avoid responsibility: you must do everything possible to avoid cross-contact and say clearly what risks there are.
What does not work
- Removing the allergen from a finished dish (for example, taking the cheese off a salad): residues remain.
- Taking the coating off a fried dish.
- Assuming a dish is fine "because it is cooked".
- Leaving the responsibility to the customer.
Key points
- Cross-contact happens through utensils, surfaces, oil, hands and air.
- Clean with detergent and water; disinfecting alone does not remove an allergen.
- Prepare the allergen-free dish first, with clean utensils and oil.
- Removing an ingredient from a finished dish does not make it safe.