Can you explain the “may contain” statements and why those with celiac disease do not need to worry about them?

May contain” or “shared equipment” statements are voluntarily included on some products to alert wheat allergic consumers of the presence of wheat in a manufacturing facility, because people with wheat allergies can have a reaction to wheat fractions other than gluten, and current testing cannot identify all non-gluten proteins in wheat. If you see this type of statement on a product that is certified gluten-free, the gluten-free certification means that it is gluten-free regardless of any “may contain” type statements and contains 10 ppm gluten or less. When present on a product labeled gluten-free in compliance with FDA regulations, the product should comply with the FDA standard of less than 20 ppm gluten and should also be safe to consume. On a product that is neither certified or labeled gluten-free, but appears to be gluten-free based on the ingredients list, this type of statement could indicate some risk, and it is safer to avoid the product.