What criteria are tested for products with the Allergy Seal of Quality?

In order for food and beverages to be certified, at least one allergenic ingredient (e.g. gluten or lactose) must be demonstrably removed by suitable processes so that a certain limit value is not exceeded. The establishment must also have an appropriate allergen management system in place. Under certain conditions, foods and beverages that do not naturally contain the allergenic substance can also be certified.

You can find the criteria for the certification of food here.