Review of proposed MRLs, safety evaluation of products obtained from animals treated with zilpaterol and evaluation of the effects of zilpaterol on animal health and welfare

The European Commission asked the European Food Safety Authority (EFSA) to review the evaluation of zilpaterol hydrochloride (zilpaterol) by the 81st meeting of the Joint FAO/WHO Expert Committee on Food Additives (JECFA) and to assess the available scientific literature in order to evaluate the potential effects of the compound on animal health and welfare. In several countries zilpaterol is used as a veterinary drug in cattle to enhance growth performance while this is prohibited in the European Union. JECFA derived an Acute Reference Dose and an Acceptable Daily Intake of 0.04 µg/kg body weight (per day) based on neurological effects seen in humans and, after carrying out an exposure assessment, has recommended maximum residue limits (MRLs) for zilpaterol in cattle of 3.3 µg/kg in kidney, 3.5 µg/kg in liver and 0.5 µg/kg in muscle. Overall, EFSA considers the approach followed by JECFA for setting MRLs for zilpaterol comprehensible. The available literature investigating the effects of zilpaterol on animal health and welfare is limited but indicates a potential increase in mortality, heart rate, respiration rate and agonistic behaviour in cattle. It is, however, not possible to clearly link the observed effects in cattle to the administration of zilpaterol at the recommended dose levels.