THE ACUTE TOXICITY OF TRIS(DIMETHYLAMINO) SILANE

animals; LC50, lethal concentration of vapor to kill 50 % of animals in the time specified; Ltso, time to kill 50 % of animals by exposure to a vapor-saturated atmosphere. The acute handling hazards of tris(dimethylamino)silane [TDMAS] were investigated. The acute male rat peroral LD50 (with 95 % con-fidence limits) was 0.71 (0.51-0.97) ml/kg, and the acute male rab-bit percutaneous LD50 was 0.57 (0.35-0.92) ml / kg. The liquid was severely irritating to the rabbit eye and skin, and the vapor severely irritating to the rat eye. The dynamically generated saturated vapor Lt50 in female rats was 12 (9.7-15) min. The effect of varying the atmospheric concentration of vapor from TDMAS on acute inha-lation toxicity was investigated by passing ordinary moist air coun-tercurrent to liquid TDMAS metered into a slightly heated glass tube. Based on nominal concentrations, the 4 hr-LC50for vapor from TDMAS was 734 (603-893) ppm in female rats by this proce-dure. Stoichiometrically, this accords with toxicity due to liberatio