Cross contamination occurs when a food that is gluten-free comes into contact or is cooked with foods that contain gluten. Obviously this can trigger symptoms in sensitive individuals.

People have different levels where gluten will upset their systems. Some are more sensitive than others. Understand that even gluten-free products can have tiny, tiny amounts of gluten (up to about 10 mg per pound of bread, for example). Since researchers estimate that it takes about 10 mg to do any intestinal damage, your child would have to eat an entire pound of that gluten-free bread to notice any symptoms. On the other hand, regular bread contains much larger amounts and a single slice might cause symptoms that last for several days.

So if a gluten-free bread is used to make french toast, for example, on a griddle where regular bread was cooked first, the gluten free bread could possibly become tainted by crumbs from the gluten in the regular bread.

Some ways to avoid cross contamination at home:

Ensure that fried foods are fried in dedicated fryers.
Buy squeeze bottles of condiments or buy separate containers for other family members.
Use a dedicated toaster, or purchase Toast-It Bags (ie. at Amazon.com), which protect GF foods from cross-contamination in the family’s regular toaster or toaster oven.
Use a separate butter dish and cutting board.
Use ceramic, glass or stone rolling pins vs wood rolling pins.
Ensure that counter space, utensils and cookware are clean.
Do not use sponges.
Avoid buying or storing in bulk bins.

And see our post about eating in restaurants or at school.