The incident occurred in a facility chrome-plating metals. At the time of the event, a metal roller was being chrome-plated. A short circuit occurred due to a defective contacting (contact rails) on the rectifier. This short circuit caused a spark to reach the surface of the electrolyte bath, and the spark ignited the hydrogen produced during chrome plating, causing an explosion.Various windows within the company were destroyed, but nobosy was injured.

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 fire developed on a hydrogen bus during filling, and was detected due to the development of smoke and a smell of burned materials.The power cable of the compressor had overheated. Two are the possible causes: (1) the cable had been wrongly installed or fixed, or (2) the electrical system had caused too high current in the cable. The corrective actions have been:(a) To ship the affected component to the manufacturing company for inspection(b) To replacement of the affected component with a new one. (c) To perform an inspection of the system on all the other buses in function.

The accidental hydrogen release occurred when testing the storage system connected to a PEM electrolyzer. The leak test consisted in filling the storage with hydrogen at step-wise increase of pressure. After the step at 3 bar (0.3 MPa), which did not reveal any leak, the storage was pressurised up to 5 bar (0.5 MPa). At that moment a hissing sound occurred from the storage at the outside of the building indicating a leak.

The incident involves a gas booster provided by a manufacturer. This device is used in the experimental platform of the project to raise the pressure in pipelines from 60 to 80 barg (from 6 to 8 MPa), allowing the gas to flow in a close loop. After 5 weeks of operation, a critical gas leakage through the vent port was detected.At the moment of the incident, the compressor was working with a mixture of hydrogen and methane (H2/CH4 blend 20/80 %v/%v). The booster was sent to the manufacturer for inspection and reparation. Severe damage in the seals of the vent port was found.

This incident occurred at the electrolyzer of a refuelling station. An employee of the electrolyzers manufacturer was on-site to conduct a reset of the plant power breaker system and to restart gas generation. Whilst putting the system into generation, a loud bang was heard. By reviewing the station CCTV evidence, a cloud of water vapour was seen being emitted from the oxygen vent line of the electrolyzer container. The gas generation system was safely shut down, and an investigation was started to understand the cause and potential impacts.

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.

At approximately 8:45 a.m. an employee was troubleshooting a thermal chamber, evaluating a Hydrogen on Demand (HOD) unit. The chamber was reported inoperative that morning. Two units were being tested on a work bench and they were connected by an exhaust hose to an HOD inside the test chamber. The gas was not properly exhausted and began to back up into the hose that was attached to the HOD. The employee removed the side panel on the chamber and it exploded while he were standing in front of it. He was killed by the explosion.