Determining the Time Required for Materials Exposed to Liquid Oxygen to return to Normal Air Ignitability by Mechanical Impact

Abstract

Catastrophic fires due to liquid oxygen (LOX) spills have occurred in the aerospace, oxygen production, transportation, distribution, and user sectors of industry as well as in the medical community. One contributing factor is that materials exposed to a LOX spill can become impact sensitive. Knowledge of the length of time necessary for common construction and clothing materials to return to normal air impact sensitivity after exposure to liquid oxygen is an important factor in avoiding these fires. Four different mechanical impact tests were performed on materials that could be exposed to a liquid oxygen spill. The materials tested were cotton muslin, floor tile with adhesive, leather, butyl rubber, industrial carpet, cork, and asphalt. The first test determined if each material was ignitable by mechanical impact in air. The second test determined the baseline energy required to ignite each material in LOX. The third and fourth tests determined the amount of time each LOX-soaked material required to return to normal air mechanical impact ignitability with an ambient-temperature test system and with a chilled test system. This paper presents the test results and a discussion.