A lightning strike caused a voltage drop on the power supply of a chlorine-alkali plant using the mercury process.The emergency electrical system was activated, though restoring the external supply voltage in less than 200 ms rendered the entire system inconsistent; some units were operating normally, but all units connected to the emergency devices (including the mercury pump) remained idle. An explosive mix of 500 kg of chlorine and an unknown amount of hydrogen accumulated inside the low-pressure chlorine treatment circuit.

DISCLAIMER: this event description is unsatisfactory. Details on the system and the real incident evolution are (still) missing. The incident affected a prototype light hydrogen vehicle in a hydrogen research centre of a university. The vehicle was a kind of a four-wheeled scooter. The fire started on the vehicle while being filled. Apparently, the hydrogen storage system was a hydrogen hydride. The site was evacuated and the building isolated from its hydrogen supply. The firefighters attacked the fire with a hose and extinguished it one hour later.

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.

A fire broke out on a transformer transforming 225,000 V into 15,000 V in a metallurgical plant. This transformer supplies electrical power the site and to a neighbouring factory. In the following three hours, staff brought the fire under control with CO2 extinguishers, the internal emergency plan was activated, and the firefighters ventilated the premises and took readings of the flames using a thermal camera. Meanwhile, however, the shutdown of the electrical installation caused the stop of the operation of an electrolysis unit using zinc sulphate.

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 fire broke out on the insulating plastic elements of an alkaline electrolyzer in a unit of a chemical plant. The shift saw the smoke from the control room. The first action was to drain the potash into a tank provided for this purpose and to shut down the electrolyzer. The on-call electrician interrupted the electricity. The safety technician brought the fire under control in less than 10 minutes using CO2 extinguishers. After approximately six hours, the unit is restarted.

This near miss occurred at the at an airport's hydrogen refilling station. Around 4:30 a.m., the hydrogen detector of the station was triggered and a sound and light alarm were activated. The hydrogen filling station was up in safe mode and the hydrogen storage system isolated. The connection pipes were purged via the vent and the power supply cut off. An on-call technician from the company in charge of managing the station arrived at 6:15 a.m., confirmed that the installation has been made safe and stopped the alarm. The leak was located on the compressors filter.

This near miss occurred at an airport's hydrogen refilling station. At 7:35, a hydrogen leak was detected by hearing whistles in the near of a pipe. The operators warned the airport firefighters ten minutes later. Upon their arrival, the firefighters set up a security perimeter of 150 m around the installation. The station is located on the border between the public space and the private space and was surrounded by a fence with a gate accessible only by a code unknown to the emergency services.

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.