The FDA is concerned with the validity of visually determined drug residue screening tests used to screen milk for antibiotics in accordance with Appendix N of the Pasteurized Milk Ordinance. On numerous occasions, the FDA has seen these differences in its laboratories when multiple individuals interpret the results from the same milk samples.
The agency is also concerned that records of visual test results are dependent on the integrity of the reader. Recently there have been instances of testers recording results before conducting the test.
Because of the FDA's concern for the integrity of test results used to determine the safety of milk, it will no longer accept visual tests for monitoring this country's milk supply for antibiotic residues. Beginning Oct 1, 2001, tests that provide a visual determination of the presence of drug residues in raw bovine milk will not be acceptable to the FDA to fulfill the drug residue screening requirements of the Pasteurized Milk Ordinance. After this date, all accepted tests must have a reader/printer that provides the records as defined in the Pasteurized Milk Ordinance.