U. S. Food and Drug Administration
Center for Food Safety and Applied Nutrition
FDA Prime Connection

HHS:PHS:FDA:CFSAN:OC:DCP:MSB

200 C Street, SW
Washington DC

M-I-98-3

April 16, 1998

TO: All Regional Food and Drug Directors Attn: Regional Milk Specialists
FROM: Milk Safety Branch (HFS-626)

SUBJECT: Drug Residue Tests for Pasteurized Milk and Pasteurized Skim Milk

The FDA has completed a review of available beta lactam drug residue screening tests for their performance with pasteurized whole milk and pasteurized skim milk.

Drug residue tests labeled for use on raw milk were submitted by their manufacturers (each selected one test), and evaluated by the FDA. Pasteurized whole milk and skim milk samples were spiked (to the tolerance/safe level) with either Amoxicillin, Ampicillin, Ceftiofur, Cephapirin, Cloxacillin or Penicillin G. Thirty replicates were tested. The following tests are acceptable for use to detect beta lactam residues when used with pasteurized whole milk and pasteurized skim milk. The number in the table indicates 1) that the manufacturer made a label claim for the detection of that drug in raw milk and 2) the percent of spiked replicates which were detected.

Drug Tolerance/Safe Level	Amox 10ppb	Ampi 10ppb	Ceft 50ppb1	Ceph 20ppb	Clox 10ppb	Pen G 5 ppb
Charm BSDA	100%	100%	Na	100%	Na	100%
Charm II Competitive	100%	100%	100%	100%	NA	100%
Charm II Cloxacillin	Na	Na	Na	Na	100%	Na
Delvotest P 5 Pack	100%	100%	Na	100%	Na	100%
IDEXX Snap	100%	100%	100%	100%	Na	100%
LacTek B-L	100%	100%	Na	*	100%	100%

1Parent Drug

* The LacTek BL detected 57% and 47% for samples spiked with Cephaparin before pasteurization, and 60% and 33% when pasteurized then spiked with Cephaparin.

Copies of this memorandum are enclosed for your distribution to District Milk Specialists, state milk regulatory agencies, State Laboratory Evaluation Officers and State Milk Rating Officers in your region. This memorandum is also available on the FDA Prime Connection Computer bulletin board system (internet address: http://www.cfsan.fda.gov), and should be widely distributed to representatives of the dairy industry, state veterinarians, state veterinary and pharmacy boards, veterinary professional organizations, and other interested parties.