Pressurization with Nitrogen as an Extinguishant for Fires in Confined Spaces

Pressurization with nitrogen has been studied as a technique for suppressing fires in confined spaces. Liquid hydrocarbon-air fires of various sizes in a gastight experimental chamber were extinguished in approximately 30 seconds by increasing the total pressure of the enclosure from l atm. to 1.35 ± 0.03 atm. The post-fire atmospheres were found to contain sufficient oxygen for support of normal human activity, while the buildup of hazardous combustion products was well below established safety levels.