A leak occurred at a of a liquid withdrawal valve of a liquid hydrogen storage tank. The hydrogen escaped at the flange between the valve body and the upper part of the valve (flange with tongue and groove). 40 kg of hydrogen were lost.The accidental release was due to the use of bolts different from those prescribed. By using the wrong ones (old bolts), the bolt material was able to flow at the specified tighteningtorque. This meant that there was insufficient tightening torque, which led to a leak.

The event occurred at the hydrogenation unit of a pharamceutical company. 145 kg of hydrogen were released the atmosphere at the gas circulation pump, due to a maintenance error . A specialist company (third-party company), had replaced the cylinder head of pump, but during assembly they did not re-isntalled the prescribed temperature sleeve for the thermometer (the temperature sleeve is the pressure-bearing element).

This event occurred when a hydrogen-carrying trailer was supplying hydrogen to a chemical plant. Instead of filling the hydrogen stationary storage, large quantities of hydrogen were transferred from the trailer into the compressed air plant network. The explosive atmosphere ignited in a compressed air consumer (a solid silo which was not containing hazardous materials).

The FCEV was travelling at approx. 75 km/h (80 km/h speed limit) on a straight, downhill part of the road. Another vehicles was waiting at a STOP sign on the right side, did not see the incoming FCEV and drove into the road at the moment of the FEV passing. The second vehicle hit the FCEV on the back right side. There were only body parts damaged and no hydrogen was released. There was no oil or other fluid spillage and no people were injured.The diagnostic system of the FCEV did not issue any alarm, and there were no warning lights to indicate a problem with the hydrogen systems on-board.

A truck-trailer carrying compressed hydrogen cylinders stopped on an autobahn and reported a hydrogen leaking from the cylinders. The highway was immediately closed in both directions. When the fire brigade arrived, the truck had stopped on a hard shoulder, and the driver had al-ready left his vehicle. A pipe was reported to be leaking hydrogen. Fire-fighters closed a valve on the affexted cylinder group to stop the leak.

On a highway, a truck loaded with 400 gas cylinders crashed at night for an undetermined cause against a concrete wall and overturned. It slipped 150 m, before several 200 litre cylinders of hydrogen caught fire and set the truck on fire as well. The police stated that it was a large fire with detonations. The 400 gas cylinders were connected together and many of the cylinders had fallen out of their racks. In order to reduce the danger of further explosions, the fire-brigade cooled the gas cylinders with water for two hours. The highway remained closed for eight hours.

A 9000 gal (34 m3) LH2 storage tank exploded during repair of the vent stack. Few days before the explosion, the tank had been filled with LH2, but later on the hydrogen released and ignited at the tank pressure control system, damaging the vent stack. To perform the required repairs, the tank had to be emptied. To this purpose the vessel was purged with nitrogen gas to display the LH2 by letting it boiling. However, the pressure inside the vacuum jacket increased because of the opening the vacuum valve. This pressure increase eventually led to the catastrophic tank rupture.

In 1987, well diggers had drilled a well for water, but had given up on one dry borehole at a depth of 108 meters. According to the source reported in the References, wind was coming out of the hole. When one driller peered into the hole while smoking a cigarette, the so-called wind exploded in his face. A huge fire followed, without smoke, looking bluish at daytime and colour and goldish at night. The crew needed weeks before being able to stop the fire and cap the well. The well remained capped until 2007, when well gas was analysed and revealed to consist in hydrogen with a purity of 98%.

This near miss occurred at metal smelting unit of a foundry. At 9:45 a.m., due to a power outage, the cooling pumps of two furnaces containing nickel and chromium stopped. One of the two furnaces was at the end of the smelting cycle. The temperature of the metal was 1300C. Due to the stop of the cooling system, water from the public network took over the cooling function, but was not efficient, causing the cooling coil to overheat.

A hydrogen leak took place on a trailer carrying compressed hydrogen, located inside the fenced perimeter of a hydrogen station. According to the company managing the hydrogen delivery and refuelling station, the leak did not pose any risk to people or the environment. A preliminary assessment identified a faulty valve s source of the leak, but t was unclear a that time if it was a single defect or a systemic (i.e. design) problem.