Hydrogen release from a CGH2 bottles trailer

A pallet containing 9 hydrogen cylinders was damaged during the operation of unloading the cylinders trailer by means of a forklift.
A 2 mm wide crack, caused by the fork, was observed on a flexible.
The fire brigade decided for an emergency and evacuation zone of 200 m.
The intervention of an expert allowed to measure a remaining pressure in the pallet of 100 bar. He tightened a nut and stopped the leak after approximately 3 hours. The amount of hydrogen released was estimated at 30 m3.

INITIATING CAUSE was the damage of compressed hydrogen cylinders by a forklift. In absence of information on driver, the ROOT CAUSE is attributed generically to a human error (wrong manoeuvre).
The responsibility of the operative management in guaranteeing safety measure able to prevent or mitigate such an event is not evident but cannot be excluded either.

cylinders

Better operative procedures used for the unloading process of compressed hydrogen bottles were required. The load/unloading process are the two operations most affected by hazards, in particularly the unloading of full bottles at the customer sites, where not always the required infrastructure is available.
In alternative, or addition, a better structural protection of the pressurised components of the pellet would increase the level of safety of those operations.