Toxic Gas and Particle Emissions from the Pyrolysis of Spacecraft Materials
XIAOLIANG WANG, Bjoern Bingham, Salix Bair, Matthew Claassen, Marit Meyer, Claire Fortenberry, W. Patrick Arnott, John Watson, Judith Chow, Desert Research Institute
Abstract Number: 283
Working Group: Combustion
Abstract
Fires are catastrophic to space activities. As mission durations increase, the chances of fire are likely to increase. In the sealed spacecraft environment, fire risks are greater than in most terrestrial locations because toxic gases and particles can quickly reach dangerous levels. Characterization of toxic pollutant emissions from fires is critical for the design of smoke detectors, respirators, fire extinguishers, and post-fire cleanup strategies. This study investigated the pyrolysis of four common spacecraft-relevant materials, including Kapton, polytetrafluoroethylene (PTFE), Teflon/Kapton/Teflon (TKT) wire insulation, and Velcro™. Multiple gases that would cause immediate concern for the health of the astronauts were detected. Kapton emitted high levels of carbon monoxide and hydrogen cyanide. PTFE and TKT emitted multiple toxic fluorine-based gases including carbonyl fluoride and hydrogen fluoride. Some of these gases had fluorination reactions with surfaces, which should be considered for surface corrosion protection and postfire clean-up procedures. Velcro™ had the highest PM2.5 emission factor. Most particles were in the submicron size range, with mode diameter peaked in the 100–200 nm range. The particles were nearly electrically neutral, carrying <0.15 net elementary charges per particle, indicating that the natural charge level would not affect ionization smoke detector sensitivity. Organics dominate the chemical composition of the emitted particulate, and their speciation and toxicity effects warrant further research.