Thirty male and 30 female rats of the Charles River CD strain (obtained from The Charles River Breeding Laboratories, Incorporation, and Portage, Michigan) weighing from 200 to 250 grams were used for this study. The rates were housed by sex, in groups of 5 rats per cage, in hanging wire-mesh cages in temperatures and humidity controlled quarters. They were maintained in accordance with the recommendations contained in H.E.W. Publication No. 74-23 (N.I.H.) entitled 'Guide for the Care and Use of Laboratory Animals.' The rats were conditioned for a minimum of 35 days prior to study initiation. Water and Purina Laboratory Chow were available ad libitum, except for an overnight period of approximately 18 hours immediately preceding oral administration during which food, but not water, was withheld. The test material was administered orally by gavage as a suspension in corn oil at the following dosage levels to male and female rats: 631, 1000, 1585, 2512, 3980 and 6308 mg/kg.