Morbidity and mortality resulting from acute inhalation exposures to hydrogen fluoride and carbonyl fluoride in rats

AbstractObjective: Experiments were undertaken to compare morbidity and mortality from brief inhalation exposures to high levels of hydrogen fluoride (HF) and carbonyl fluoride (COF2).Methods: Rats from both sexes were exposed for durations of 5 and 10 min to nominal concentrations of 10,000 to 57,000 ppm HF or 500 to 10,000 ppm COF2. Respiration was monitored before, during, and after exposure. Animals were observed up to 6 days post-exposure. Terminal blood samples were collected for routine clinical chemistry and hematology. Post-mortem lung fluoride concentrations and lung weights were measured, and gross pathology noted.Results: Both gases produced respiratory depression independent of concentration or exposure duration with minute ventilation decreasing to approximately 50% of baseline. Estimated mixed-gender HF and COF2 10-min LC50’s were 48,661 ppm and 1083 ppm, respectively. HF mortalities were generally delayed 3 to 4 days post-exposure, while COF2 mortalities occurred during or briefly after ex...