Residue Testing Harmonized

The Food Safety and Inspection Service (FSIS) in June implemented a modified approach to testing meat carcasses for the presence of violative new animal drug residues. This approach harmonizes FSIS testing and disposition procedures and the Food and Drug Administration target tissue/marker residue policy.

FDA determines whether new animal drugs are safe for use in specific animals and establishes tolerances for drug residues that remain in edible tissues of treated animals postmortem.

For any new animal drug with an FDA-established marker residue tolerance in a specific target tissue (typically the liver or kidney) that does not also have an established tolerance in muscle tissue, or for which there is no official analytical method for muscle tissue residues, FSIS will test only the target tissue. If the residue in the target tissue exceeds the FDA tolerance, FSIS will consider the entire carcass to be adulterated.

For any new animal drug that has an FDA-established muscle-tissue residue tolerance as well as an official analytical method for detecting muscle residues, FSIS will test the muscle tissue. If the residue in the muscle does not exceed the tolerance, FSIS will release the muscle tissue and allow it to be distributed for human consumption.

For the new animal drugs where tolerances have been established for all edible or muscle tissues but not for a target tissue, FSIS will collect and monitor multiple samples of edible tissues to determine residue. 

Only seven of the veterinary drugs commonly used in cattle have an FDA established marker residue tolerance in a target tissue, but do not have an established tolerance set for the muscle tissue. These drugs are: apramycin, carbadox, fenbendazole, melengestrol acetate, morantel tartrate, oxfendazole, and tiamulin.