A hydrogen cylinder was initially located in an adjacent laboratory, with tubing going through the wall into the laboratory in use. When the cylinder was moved to the laboratory in use, a required leak check was not performed. Unfortunately, a leak had developed that was sufficient to cause an accumulation of hydrogen to a level above the Lower Flammability Limit. The hydrogen ignited when a computer power plug was pulled from an outlet. The exact configuration of the leak location and the outlet plug is unknown.

Incident Date
Ignition Source
Spark from pulling computer power plug from outlet
Lessons Learned

Hazard analysis should consider potential leak locations, potential ignition sources in the vicinity, and the potential for accumulating flammable gases in that area.

Users should leak-check all cylinders upon installation. This event would have been avoided if personnel had followed internal procedures/requirements.