10-DAY AND 90-DAY TOXICITY STUDIES OF 1,2-DICHLOROETHANE IN SPRAGUE-DAWLEY RATS

Male and female Sprague-Dawley rats received 1,2-dichloroethane in cor n oil by gavage for 10 or 90 consecutive days. The doses for the 10-da y study were 10, 30, 100, and 300 mg/kg; the 90-day study doses were 3 7.5, 75, and 150 mg/kg. There were ten animals per sex per dose group. In the 10-day study, all female animals died in the high dose group a nd only 2 of 10 males survived. Final body weights and weight gain alo ng with hematology and clinical chemistry findings were not different from controls. The only relative organ weight which was significantly different was the liver in males exposed to 100 mg/kg. The main histop athological lesion exhibited was multifocal to diffuse inflammation of the mucosal and submucosal layers of the forestomach in the 100 mg/kg dose group. This change was minimal in both males and females. In the 90-day study there were no treatment-related effects pertaining to cl inical observations. Body weight gain and total food consumption were significantly decreased in high dose males. There were slight but sign ificant differences in hemoglobin, hematocrit, red blood cell count, p latelets, albumin, and alkaline phosphatase values in the 75 and/or 15 0 mg/kg groups in one or both sexes. In males, relative brain, kidney, and liver weights were significantly increased at 75 and 150 mg/kg. T here were also differences in spleen, adrenal, and testes weights (abs olute and/or relative). In females, absolute and/or relative kidney an d liver weights were significantly increased at 150 mg/kg (liver) and at 75 and 150 mg/kg (kidney). There were no apparent treatment-related effects pertaining to mortality, ophthalmology, gross pathology, or h istopathology.