Acute and Subacute Inhalation Toxicity of Highly Purified Phosphine (PH3) in Male ICR Mice

Abstract

Acute and Subacute Inhalation Toxicity of Highly Purified Phosphine (PH3) in Male ICR Mice: Kazuyuki Omae, et al. Department of Preventive Medicine and Public Health, School of Medicine, Keio University—The acute and subacute inhalation toxicity of highly purified phosphine (PH3, CAS No. 7803‐51‐2, 99.995%) in male ICR mice was investigated. LC50 for one‐hour exposure was greater than 59.2 ppm and that for four‐hour exposure was between 26.5 ppm and 33.4 ppm. Experiments involving acute exposure to 25 ppm PH3 for one, two, four or eight hours, and subacute exposure to 5 ppm PH3 for six hours/day, five days/week, for two or four weeks were conducted. All mice subjected to acute eight‐hour exposure died but a histopathological examination failed to reveal the actual causes of death. In the nasal cavity, exposure‐time related inflammatory changes were observed in the acute two‐, four‐, and eight‐hour exposure groups, and in the subacute four‐week exposure group. Other his‐ topathological, hematological, and serum biochemical examinations did not reveal PH3‐related changes. Further study is necessary to assess the actual effects of PH3 on the cause of death.