Toxic Combustion Products Testing of Polymers Used in Oxygen Systems A Review of Testing at WSTF

Abstract

This paper reviews some of the toxic combustion products testing, in ambient pressure, previously performed at NASA White Sands Test Facility (WSTF). The paper also presents some results from recent toxic combustion products testing in high-pressure oxygen of polymers typically used in oxygen systems. The review shows that generation of combustion toxicants is both material-dependent and temperature (or fire)-dependent. Fire conditions, the location and means of sampling, and analytical instruments used are the controlling parameters for the analysis of toxic combustion products. FTIR can provide continuous, real-time measurements of combustion product gases; however, it is difficult to obtain quantitative FTIR measurements. Appropriate sampling probe, filters, gas transfer line, and FTIR software are definitely needed. Nondispersive infrared (IR) is an effective tool for real-time carbon monoxide and carbon dioxide measurements. Combustion products analyzers (electrochemical method) and Draeger® Tubes are limited to the analysis of light combustion product gases, and they are less efficient compared with FTIR. The results of combustion testing in high-pressure oxygen environments show that combustion of polymers in high-pressure oxygen environments generated much less carbon monoxide and hydrogen cyanide. The toxic potency of the combustion gas is presumably lower than that of combustion gas generated from ambient-pressure oxygen (or air) environments.