Abstract
Rats, rabbits, and guinea pigs were exposed seven hours per day, five days per week for periods up to six months duration to atmospheres containing boron trifluoride in concentrations calculated to be 12.8, 7.7, or 3.0 ppm. Analysis showed concentrations to be about one-half of these levels. The major effect of repeated inhalation was respiratory irritation causing injury ranging from death to a slight increase in pneumonitis. On basis of the study, a value of 0.3 ppm is tentatively suggested as a threshold limit value for boron trifluoride.
