Factors Affecting NVR Contaminant Fire Risk
SourceCleanliness is considered a foundational element of a safe oxygen system or component. Contaminants, particularly in the form of hydrocarbon oil or grease surface films, are considered more ignitable than the bulk materials of a component or system. Furthermore, ignition of oil or grease films is often an initiating event in fires where a kindling chain develops, eventually involving the bulk materials of the component or system. This paper describes several primary factors related to the fire risk of predominantly nonvolatile residue (NVR) contaminants. The present understanding of these factors is reviewed with discussion of applicable historical research, and new data are presented for some factors. The combined collection of research is then discussed in the context of industry standards and guidelines regarding contaminant cleanliness levels.