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).

A hydrogen leakage caught fire in the hydrogen compressor area of the continuous reforming unit. The reforming unit and the hydrocracking unit were immediately stopped. The hydrogen flow was cut off, a protective combustion was carried out and the fire was completely extinguished after approximately 20 minutes, with no casualties. The cause of the accident is being investigated.

The broke out at a hydrogen compressor of the reforming unit of the refinery. Following the safety procedures, the emergency stop of the unit was activated and the unit was decompressed using a safety flare. The emergency plan was kept for an hour. A security perimeter is in place. The isolation of the compressor was started automatically. The isolation of the discharge circuit was successful, but the suction circuit could only be partially closed due to a block of a valve. The operators then closed manually the suction valve, by removing the excess of grease that had been applied to it.

The incident occurred at company producing specialised products for aerospace and aeropwer applications. An employee was operating an induction brazing machine under hydrogen atmosphere when an explosion occurred.

A fire broke out following a hydrogen leak on the cyclododecane unit in a chemical plant. A plume of smoke became visible outside the site. The fire was brought under control by putttng the unit in safe mode, implementing the internal resources available on site (monitor lance, sprinkler ring and extinguishers), and finally by the inervention of the internal firefighters. The staff was evacuated and the internal crisis unit triggered. The fire was extinguished in 30 minutes. The post-incident analysis revealed a hole in the connection of the vent manifold, upstream of the evacuation pipe.

Around 4 a.m., a major leak occurred at the outlet of the diesel hydrodesulfurization furnace in a refinery. The goal of this unit is to lower the sulfur content of diesel fuels produced in other units, by a catalytic reaction in the presence of hydrogen. At the moment of the leak the furnace was restarting. The alarms of the temperature sensors at the oven outlet were triggered. At 4:08 a.m., the operator shut down the hydrogen compressors and diesel charging pumps, closed the supply valves and called the emergency status. The first emergency operation was to decompress the unit.

A gas mixture (25% nitrogen, 73% of hydrogen, 2% methane) leaked, due to the ejection of the check valve from its connection with the inlet pipe. A large amount of the gas mixed with air and ignited, probably due to sparks generated by the ejected check hitting a metal pipe. It followed an explosion. Its pressure wave hit a gas pipeline causing its fracture and a fire. After about 1 hour and 30 minutes the fire was under control. The shockwave from the explosion caused a gas pipe at the back of the workshop to crack and leak, causing a large fire.

A mixture of mainly carbon monoxide and hydrogen was released from a pipeline transferring process gases in a not further specified unit of a chemical plant, generating a flammable mixture which ignited possibly due to static electricity and resulting in 22 deaths and 8 injuries.

The day before the incident, the outlet pipe connected to methanation reactor started leaking gas, which contains hydrogen. The leak was temporarily eliminated by a pressurised plug. On the day of the incident, the pipe leaked again, and the same plugging method was still used to stop the leak. This occurred without shutting down the unit and taking safety measures. Approximately one hour later, a sudden explosion occurred at the inlet line of the methanation reactor.

the explosion occurred inside the lower hydrogenation tower of a hydrogen peroxide unit, damaging the distribution tray inside the tower. 4 were killed and 2 injured, the direct economic loss was 488.2 million yuan. The hydrogenation tower is part of the hydrogen peroxide plant.