This document is one of the three publications prepared by the forty-eighth session of the Joint FAO/WHO Expert Committee on Food Additives (JECFA), held in Geneva, February 1997, and dedicated exclusively to the evaluation of, veterinary drug residues in food. The report of the meeting will be published in the WHO Technical Report Series, and the toxicological monographs as No. 39 in the WHO Food Additives Series. Residue monographs in this document provide information on chemical identity, properties, use, pharmacokinetics, metabolism, tissue residue depletion of, and analytical methods for substances indicated on the cover. This publication is meant for regulatory authorities, veterinary drug researchers and any other concerned persons who wish to gain information and insights into the needs and problems involved in establishing maximum limits for veterinary drug residues in food.