Results give Washington dairy cattle all clear from toxic substances

The Food and Drug Administration's Forensic Chemical Center (FCC) laboratory in Cincinnati has completed its testing of milk samples from cows exposed to a toxic substance in Washington State. The results of the tests reveal no identifiable risk from this agent associated with the milk from any of the exposed cows.

The FCC lab, which has been working around the clock since Sunday, June 20th, tested samples from exposed animals and animals not exposed. Initial testing was focused on identifying the toxic substance. An ear tag containing a residue of the toxic substance was removed from a dairy cow directly exposed to the toxic agent and tested. Milk from dairy cattle directly exposed to and made ill by the toxic agent was tested, as was milk from an additional group of cattle that came into contact with the toxic agent but did not become ill. In addition, milk samples from unexposed healthy animals were also tested as a control group, for the sake of comparison.

FDA's testing of residues from directly exposed animals identified the substance as a strong oxidizing chromium compound. Consequently, FCC focused on analyzing milk samples for the presence of chromium.

Because the investigation of this case is continuing, precise test results for individual samples will not be released. Concentrations of chromium in all samples of milk from dairy cattle directly exposed to and made ill by the toxic substance were well below the level of 100 parts per billion allowed for drinking water by the Environmental Protection Agency.

Chromium levels in all milk samples tested from the cows that came into contact with the toxic substance but did not become ill were below the minimum detection level of less than 1 part per billion.

These results are reassuring, especially since milk would have been diluted some 5,000 to 50,000 times when it is combined with milk from other farms in preparation for processing.

Some milk from healthy animals in this herd has been voluntarily held pending the test results. FDA's Seattle District today is advising any firms that have been holding milk or milk products that those products may be released into commerce. No milk from the 10 ill animals has entered the food supply.