Update evaluation of trenbolone acetate, zeranol and melengestrol acetate as growth promoters (considerations concerning the "hormone issues" betweenEU and USA at the WTO

Estrogens and androgens are efficient growth promoters in animal production . The improvement of protein anabolism and N-retention provide economic and ecologic advantages. Nevertheless there are scientific arguments to mainta in the EU import ban of meat from animals treated with the approved compoun ds foreign to the body trenbolone acetate, zeranol and melengestrol acetate . There is demand for an updated and more strict risk assessment as perform ed at the first approvals by the Food and Drug Administration in the USA. T he harmless and complete removal of pellet-rests from animal's body is not secured just by the instructions; the milligram order of magnitude of those residues represents the quantitatively most important risk potential. As a matter of fact there are missing controls and reliability tests of the app lication routine in practice. The risk resulting from improper manipulation s and from possible introduction of residues of the implantation site into the route of food processing has not been defined. Further research is stil l demanded concerning the positive results of mutagenicity tests of trenbol one, concerning the potential of formation of long chain and long acting es ters of trenbolone and zeranol stored in fatty tissue, and concerning the i mportance of the recently discovered additional receptors for related compo unds. The covalent bound residues of trenbolone to DNA and proteins has to be reconsidered. Those properties hardly fulfill the consumers' expectation s for genuine food. Residues in meat detectable even after proper applicati ons diminish the chance of control of illegal and hence risky application p ractices of those compounds; this could increase the risk potential. Recent ly a scientific publication from an American export country informed about the increase of illegal treatments with trenbolone.