Normally hydrogen fires are not extinguished until the supply of hydrogen has been shut off due to the danger of re-ignition and explosion. During a gas leak/fire, it is important to shut off the source of the hydrogen if it is safe to do so. If the leak cannot be stopped, the danger of a fire (or an explosion if the unburned hydrogen gas is leaking into a poorly ventilated confined space) would be very high. If a leak cannot be stopped, fire extinguishing is impossible and only prevention of fire spreading is possible. It is also difficult to detect a gas leak from thermally insulated piping at an early stage.
Countermeasures which were employed to prevent future occurrences include:
Improving management of construction at turnaround to prevent improper gasket installations.
To detect gas leaks in piping systems covered with thermal insulation, inspection windows were installed in the insulation and gas leak checks were strengthened.