Several food proteins are used as food additives or may be contained in foods as contaminants. These masked allergens are at high risk of inducing severe clinical reactions: acute asthma, laryngeal angioedema, anaphylactic shock or even death. The present regulation requires labelling only if the level of food ingredients is superior to 25% of the final product. Several immunologic methods can detect low levels of proteins, equal or inferior to 2%. However a level of 1% or less may be noxious, suggesting a need for a specific line of food products which could be guaranteed free of ... and which might be recommended to patients with food allergy.