Regulatory problems caused by contamination, a frequently overlooked causeof veterinary drug residues

The occurrence of violative residues of veterinary medicines and other, una uthorised, drugs in food of animal origin is an issue of popular concern wi thin the European Union. Violations can occur as a result of improper use o f a licensed product or through the illegal use of an unlicensed substance. However, a "violative" analytical result does not necessarily mean that ab use has occurred. Contamination of animal Feedingstuffs, environmental cont amination and animal-to-animal transfer of drugs can also cause residue vio lations, This paper reviews these inadvertent causes of residues violations in food, and includes data generated using chromatographic and non-chromat ographic methods of analysis. Crown copyright (C) 2000 Published by Elsevie r Science B.V. All rights reserved.