PRELIMINARY ASSESSMENT OF A PYROTECHNICALLY GENERATED AEROSOL FIRE SUPPRESSANT

Abstract

Fischer 344 rats (approximately 250-300 g) were exposed to the aerosol resulting from the pyrolysis of SFE Formulation A at a loading of 50 or 80 g/ m3. Animals were exposed for 15 or 60 min and euthanized 1 h postexposure. The exposures were conducted in a 700-L inhalation chamber under static conditions. Aerosol samples were collected and analyzed for mass concentration and size distribution (mass median aerodynamic diameter, MMAD, and geometric standard deviation, sigma g). Lungs were collected for wet/ dry weight ratio analysis, and nasal turbinates were prepared for histopathology examination. No deaths occurred during the study or postexposure observation period. Animals exposed to SFE exhibited signs of dyspnea, lack of coordination, and lethargy. As the load and exposure length increased, these signs became more pronounced. No lesions were noted in the trachea, lung, heart, and abdominal organs upon gross examination. No histopathological abnormalities were noted in the nasal turbinates. Changes in blood gases, blood pH, the various hemoglobin types, and serum glucose were noted. Of these changes, carboxyhemoglobin was the most significant, with an increase of 40%. The remaining serum chemistry parameters evaluated were within their respective biological ranges. Wet/dry lung ratio showed no difference between control and exposure groups.