Physicochemical Properties of SFE Fire Suppressant Atmospheres in Toxicity vs Fire Extinguishment Tests: Implications for Aerosol Deposition and Toxicity.

摘要

Comparisons were made between the physicochemical properties of Spectronics Fire Extinguishant (SFE) atmospheres generated either in a fire extinguishment or inhalation toxicity assessment regimen. Aerosol and gas phase components in the atmospheres were dynamic as opposed to steady-state, having varying rates concentration change. Fire extinguishment test conditions closely approximate those proposed for deployment of SFE as a fire extinguishing agent. Significant differences in aerosol mass concentration, size distribution and shifts in size distribution were found between the two types of atmospheres, each generated at two comparable target (nominal) concentrations. Likewise, differences in CO2 and CO concentration and dissipation rates of these gases also were found between the two types of atmospheres. A series of theoretical calculations of CO2 induced hypercapnea were developed as a basis to examine possible interaction of the components of the atmospheres. A hypothetical case for aerosol deposition rate and carboxyhemoglobin formation and changes in the rates of these phenomena was formulated for each atmosphere.