A plume of hydrogen gas escaped from the offloading valve of a liquid hydrogen delivery truck while transporting hydrogen to a commercial facility. The plume ignited, resulting in a flash and concussion loud enough to be heard inside the nearby building and to set off the building’s seismic event detectors. A small amount of hydrogen gas continued to escape from the trailer tank and burn until a company specialist arrived to manually shut off a critical valve almost eight hours later. In the mean time, emergency response crews called to the scene sprayed water across the hydrogen tank as a precautionary cooling measure. The actual cause of this incident appears to have been primarily driver error. A number of steps required as part of the standard safety procedure were either incorrectly applied or omitted altogether. In any case there was no crash or any compromise in the integrity of the fuel tank aboard the truck trailer.

Incident Date
Aug 06, 2004
  • Piping/Fittings/Valves
  • Valve
  • Vehicle & Fueling Systems
  • Liquid Hydrogen Delivery Vehicle
Damage and Injuries
Probable Cause
Contributing Factors
When Incident Discovered
Lessons Learned

Attentiveness to proper procedure would have prevented this incident.
This incident also underscores is the need for rigorous training on hydrogen properties and behavior, not only for the operators of fueling equipment but also for emergency responders and the general public. The physical and chemical characteristics of hydrogen are different from those of fossil fuels and must be communicated, understood, and accounted for in hydrogen handling and use.