It is important that products with the Allergy Seal of Quality never have traces of the allergen that is being advertised. For example, traces of wheat or spelt are not allowed in gluten-free foods. However, certified products may contain traces of other allergenic ingredients because a person with a lactose intolerance, for example, does not automatically have avoid all other allergenic ingredients that require declaration. In this way, a wide range of controlled and certified foods can be offered to the various people affected.

See question: Are the products completely allergen-free?