Abstract Assessment of the Reproductive Toxic Potential of Dermally Applied 2-Hydroxy-4-methoxybenzophenone to Male B6C3FI Mice. Daston, G. P., Gettings, S. D., Carlton, B. D., Chudkowski, M., Davis, R. A., Kraus, A. L., Luke, C. F., Ouellette, R. E., Re, T. A., Hoberman, A. M., and Sambuco, C. P. (1993). Fundam. Appl. Toxicol. 20, 120-124. The potential of 2-hydroxy-4-methoxybenzophenone (HMB) to cause male reproductive toxicity was assessed in B6C3FI mice. HMB was administered topically for 13 weeks (5 days/week) to groups of 10 mice each at dosages of 0, 10, 20, 100, or 400 mg/kg/day. Additional high dosage and control mice were also included and euthanized at interim time points to characterize the time course of any effects. After 91 days (or at interim periods) mice were euthanized and reproductive organ weights, cauda epididymal sperm concentration and proportion of motile and abnormal sperm, and testicular spermatid concentration were determined. Testicular histology was evaluated in fixed tissue. HMB treatment had no effect on body weight gain or any of the male reproductive parameters assessed at any time point. These results indicate that topically applied HMB has no reproductive toxic potential in male B6C3FI mice at dosages as high as 400 mg/kg/day.