Toxic gas and particle emissions from the pyrolysis of spacecraft materials

Fire is an imminent risk in space activities. Toxic gas and particle emissions can quickly reach dangerous levels in sealed environments. To improve smoke detection, protection, and post-fire cleanup, understanding the emissions from the pyrolysis of spacecraft-relevant materials is crucial. This study investigated the pyrolysis of four common spacecraft materials, including Kapton, polytetrafluoroethylene (PTFE), Teflon/Kapton/Teflon (TKT) wire insulation, and Velcro™, to identify, evaluate, and quantify their gaseous and particulate emissions. 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, while Velcro™ had the highest PM_2.5 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 less than 0.15 net elementary charges per particle. Organic compounds predominated in the particle compositions.