Document mBNjJkpyznZRMJ5Ra5VVg0nrb

cc: ETHYL CORPORATION Dr. A. J. Haefner A. Iluylunciik Dr. W. E. Rinehart Mr. H. H. Wall INTEROFFICE To Dr. M. F. Gautreaux Address From D. E. Park Subject Rodent Testing - Toxicity Studies Address Date May 15, 1974 I would like to pass along a few thoughts on the rodent testing study concerning some facets of the test that bother me. The first point is that I do not understand why levels of 30 and 40 ppm have been skipped. The second point is my understanding that these tests will be conducted with the mice in large cages which do not provide for separation of the rodents. The tests are controlled in such a way that the mice are not fed during the seven-hour test period each day on the basis that feeding the rodents would interfere with the test results. When the mice are not separated they eat each other. I submit that the mice being eaten are contaminated food also. If contaminated food invalidates the test, then how can non-separation of the rodents be justified. r Gordon Hughmark tells me that the lack of water during tests for lead has a drastic effect on the results. I don't know if the rodents in previous tests for VC1 were allowed to drink or not. If they were allowed to drink, they were receiving contaminated food, in effect. If they were not allowed to drink, the results of the test were much more severe than reality would dictate. Henry Wall showed me some data acquired from Solvay which reports allowable levels of various materials as determined by the Russians. As I understand it, the Russians test on humans and do so by starting at extremely low concentrations and define as the maximum allowable level that concentration at which there is an initial reaction. The Russians have ` set a limit of 30 ppm on VC1. This information has been given to Gordon Hughmark for the statistical studies that E&MS are making of the previous mice, rat, and hamster studies. DEP:jht D. E. Park VC1750