What is cross contact?
Food allergy cross contact is when one food accidentally comes into contact with another and some proteins are left behind. You might have heard of this as “cross contamination”, which is a term that people have used in the past. These days cross contamination is mainly used (especially by people in the food industry) when talking about viruses or bacteria that can cause food-borne illnesses. So the current term for food allergens which get transferred from one food to another is “cross contact”.
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Why is it so important to avoid food allergy cross contact?
People with food allergies can have allergic reactions to even the smallest amount of an allergy causing food.
Allergens can be almost invisible. If for example someone uses a knife to spread butter, wipes it off and then uses it again to spread a dairy free spread, the knife still has milk protein on it. This can be enough to cause an allergic reaction.
Symptoms of allergic reactions include:
MILD OR MODERATE
- swelling of lips, face or eyes
- hives or welts
- tingling mouth
- vomiting or abdominal pain (*this can be a sign of a severe reaction to insect stings)
- difficult or noisy breathing
- swollen tongue
- swelling/tightness in throat
- wheezing or persistent coughing
- difficulty talking or hoarse voice
- persistent dizziness or collapse
- pale and floppy (young children)
The most serious type of allergic reaction is anaphylaxis, which can be life threatening.
How does cross contact happen?
Food allergy cross contact can happen:
- when you are preparing food, including food that is going to be cooked. The cooking process does not eliminate the chance of the allergen causing a reaction when the cooked food is eaten;
- during cooking, from leaks or splatters from other dishes, or even from the cooking surface (like a barbecue grill);
- while you are serving the food;
- during storage, including in the fridge or freezer.
It can be direct. If you mistakenly put a slice of cheese on someone’s sandwich and then just take it off, the cheese has been in direct contact. It isn’t enough to simply remove the offending food from a dish that has already been prepared. Scraping the nuts off the top of the cake definitely doesn’t cut it.
Cross contact also happens indirectly or by accident. For example if you use a knife to cut the cheese sandwich and then just wipe it off before slicing the allergy free sandwich. Wiping isn’t enough. You would need to properly clean the knife in soapy water first or use a different knife;
How to avoid cross contact at home
With some allergies, such as a peanut or tree nut allergy, you might choose to avoid that ingredient altogether in your home. For other allergy causing foods such as wheat, milk and eggs, you might not be able to do this. We have one child with multiple severe food allergies, including to milk and egg, but the rest of the family still eat these foods regularly.
All utensils need to be cleaned in hot, soapy water. This includes chopping boards, pans, knives and any other kitchen item that will come into contact with the food.
Be aware of hand hygiene too. If you have touched an allergy causing food during your food preparation, make sure to wash your hands with warm soapy water before preparing the allergy free meal. (Note: alcohol based hand sanitiser does not remove food proteins!)
A safe option is to have separate utensils that are only used for cooking allergy free meals. For example, we have a separate bamboo steamer with our child’s name written on it (as our other steamers are sometimes used for foods that might contain sesame, another of his allergens).
Another great idea for avoiding food allergy cross contact is to use colour coding. Chopping boards, mixing bowls and knives all come in different colours and can make it easy to remember which utensils are used when making an allergy free meal.
Using colour coded chopping board mats is an easy option that can be cleaned in the dishwasher. These even come with food icons for gluten and gluten free, but even just the different colour can be a visual reminder when keeping food separate.
Coloured knives not only help you remember which knife you used for which cooking task, they also look great in the kitchen. I love the look of this set of 10 colourful stainless chef knives.
When cooking for someone with a food allergy at the same time as other foods, cook the allergy free meal first. For example, when we make toasted sandwiches in our sandwich press, we will do the dairy free cheese version separately first.
Be careful not to let anything leak or splatter from the other meals into the allergy free meal. This might mean you need to place items on different shelves in the oven. We do pizza with dairy free cheese on the top shelf and the regular cheese underneath. Sometimes you will need to simply cook the meals at different times if cross contact is too hard to avoid.
Heading to a barbecue at a friends’ house or at a park? If you can’t clean the barbecue grill first and cook your meal separately, be prepared and take your own grill mat.
After taking all that trouble with the preparation and cooking, it goes without saying that you shouldn’t serve your allergy friendly meal on a shared plate or platter with other foods. And always use separate knives or serving utensils.
It is really important not to share food, drinks or utensils. One thing that is sometimes overlooked is drinks. Definitely never drink out of other people’s glasses, cups or drink bottles. Remind your children and their teachers about this too.
Keep allergies in mind even when doing the dishes. You don’t want to wash the dishes covered in food allergens and then use the same water to wash the allergy safe utensils and pans. We always wash the allergy free dishes first, or use the dishwasher.
Make sure you clean all bench tops or food or food preparation surfaces thoroughly too.
When you are tidying up, be sure all ingredients are clearly labelled and kept separate. Don’t store foods or ingredients where they might leak on to other food in the fridge. Cover everything well.
Allergy stickers and labels are a great way to label ingredients in the pantry as well as left overs in the fridge or freezer.
Food allergy cross contact when eating away from home
When you live with food allergies every day, avoiding cross contact becomes second nature. It is just instinct to reach for a separate spreading knife or to cook food for someone with food allergies first. But never assume that other people understand what is involved or how serious the consequences can be.
If you are planning to eat away from home with food allergies, make sure you disclose your food allergies in advance and explain about cross contact risk. Ask questions. Don’t be afraid to ask for your food to be prepared with separate utensils and cooked in a separate pan.
Chef cards are a fantastic tool to help you communicate food allergies clearly to kitchen staff. Many of them include information about cross contact too. Find out more about chef cards in our post – Why we love food allergy chef cards.
And don’t forget to take your EpiPens if they’ve been prescribed for your food allergies – read about why you should have two with you in our post Making friends with your EpiPen.