ACUTE INHALATION TOXICITY OF RED PHOSPHORUS SMOKE

The acute inhalation toxicity of smoke generated from pure unform ulated red phosphorus ignited in an air stream was investigated in male rabbits, rats, m ice, and guinea pigs, exposed for 1 h. There was a wide range of 1h-LC values 5 0 among the species. Expressed as phosphorus, they were 1689 mg/m 3 (rabbits), 1217 mg/m 3 (rat), 271 mg/m 3 (mouse), and 61 mg/m 3 (guinea pig); expressed as ortho-phosphoric acid equivalents, the values are 5337, 3846, 856, and 193 mg /m 3 . In rabbits, rats, and m ice that died, there were sim ilar histopathological findings in the respiratory tract; laryngotracheal epithelial or mucosal necrosis with acute inflammatory cell infiltration, pulmonary congestion and edema, alveolar hemorrhages, alveolar wall polymorphonuclear cell infiltration, bronchiolitis, and macrophage aggregations in alveoli and bronchioles. These findings are compatible with respiratory tract injury from the corrosive effects of phosphoric acids in the smoke com position. In contrast, guinea pigs at t...