This Technical Memorandum was originally prepared as an Annex on the topic of Hydrogen Embrittlement for the AIAA Guide to Safety of Hydrogen and Hydrogen Systems (G-095-2004), then in revision [1]. The Guide establishes a uniform NASA process for hydrogen system design, materials selection operation, storage and transportation, and represents a broad collection of aerospace acumen.

In collaboration with Parker Hannifin Corporation, the Fire Safety Branch of the FAA conducted testing to evaluate the effects of three potential failure conditions of hydrogen proton exchange (or polymer electrolyte) membrane fuel cell stacks supplied by Nuvera Fuel Cells. The three conditions examined were a loss of coolant to the stack, short circuit, and a crossflow condition.

Sodium chloride and four or five other particulate materials have been used successfully as fire suppression agents for specific combustible metal fires. The certification testing and National Fire Protection Association recommendations for using these suppression agents are summarized here. The sodium chloride based agent and ordinary sand have also been used in some sodium hydride fires, and in a sodium hydride fire test series.