A small electrical fire occurred (due to what is believed to be an electrical short circuit) inside a fuel cell test stand. Subsequently, a nearby hydrogen line made of flexible tubing was melted through and ignited the hydrogen, causing a small fire.

The electrical fire was easily extinguished. The hydrogen flame was extinguished by snuffing the flame, shutting off the gas lines and power to the test stand. No one was injured, but damage was incurred in the test stand.

Causes

An electrical short circuit occurred, causing a small electrical fire.
Electrical fire caused a flexible tubing hydrogen line to melt, thus exposing hydrogen to the fire.

A pinhole at the base of a hand-held hydrogen torch, allowed hydrogen to leak. In the process of lighting a second torch, the leaking hydrogen was ignited. The operator, being startled by the "pop" of the lighted hydrogen allowed the #2 torch to drop and hang by its hose support approximately 6" from the floor. The hydrogen and oxygen hoses on the #1 torch were burned through and hung approximately 12" from the floor. The free burning #1 hose burned the #2 hydrogen and oxygen hose assembly through, causing both hoses assemblies to burn without valve control. The hose size is 1/4" and is used in various areas of the plant.

A facility uses small crucibles to heat precious metals within a fume hood, with natural gas as the fuel source for the Bunsen burner. Hydrogen is fed into the crucible at low pressure (<20 psi) to control the atmosphere within the vessel in order to prevent oxidation. The hydrogen is routed through a manifold with flexible tubing, which is connected to a ceramic tip and fitted into the crucible through a small opening in the crucible's lid. The hydrogen is consumed in the process. The facility believes that the hydrogen tubing developed a leak which eventually ignited. The plastic interior of the fume hood ignited and started to spread. The person working in the area shut off the natural gas and hydrogen (they had valves at the hood) and used a halon extinguisher in the view more