Explosion in a industrial gases production plant

Gaseous hydrogen leaked from an oil pump part of the filling and conditioning system in a industrial gases production plant. The released hydrogen ignited and exploded.
The cause has been a human error: an operator turned gave a valve a ¼ turn, connecting containers, which were not empty, with the pump.
The hydrogen release occurred in an open space under an awning. This caused the flammable mixture to explode producing a fireball of 10 m of diameter. 2 workers were injured but the material damage was limited to a door and a small room.

A valve was misplaced by the operator, releasing hydrogen under the canopy.

Oil pump, gaseous hydrogen storage, pump

First degree burns for two employees

No attempt to stop the leak was made, because the safest way to deal with was to allow hydrogen to vent and empty the cylinders without