Abstract
The four-hour LC50 values for ChR-CD male rats for phosphine, phenylphosphine and triphenylphosphine have been determined to be 0.44 micromoles per liter (µM/liter), 1.56 µM/liter and 47.8 µM/liter respectively. The dose-death curves are parallel. During exposure, all three caused clinical signs indicative of mild respiratory irritation. Triphenylphosphine also caused severe weight loss immediately after exposure, followed by normal rate of weight gain. No histopathologic effects due to exposure were seen in any of the tissues examined after single exposures to any of the three compounds. Phosphine and triphenylphosphine caused mild weight loss during a 10-day exposure period followed by normal rate of weight gain during a 14-day recovery period. The phenylphosphine exposures caused a decreased rate of weight gain during the exposure period which returned to normal during the recovery period. Silver nitrate paper was found to be unsuitable for field analysis of phenylphosphine.