[Residues in products of animal origin (author's transl)]

Products of animal origin may contain a variety of substances regarded as 'residues': traces of veterinary drugs and their metabolites, environmental contaminants, traces of compounds having injurious effects, which have their origin in the manufacturing process, and mycotoxins. Some of these substances are carcinogenic, others may impair the functions of organs or cause disturbances of hormonal balance. Antibacterial substances may induce resistance of pathogenic agents and, finally, a number of substances give rise to sensitivity reactions. Standards for permissible amounts are required in several cases; a number of substances should be completely omitted so that their use should be prohibited; adopting the concept of 'zero tolerance', however, may present problems. Extensive analysis is only practicable so far in a few cases. Rapid screening procedures will have to be developed in the future, in which immunochemical methods may play a particularly important role.