The truck was carrying 25 m3 of liquid hydrogen and was parked in the parking lot of a road restaurant. The hydrogen escaped through the safety devices of the tank and then dispersed (the weather was wet and there is fog). Technicians from the charter company degassed the tank until the leak stopped, then escorted the truck to a technical centre. A crack in the inner tank causing a pressure build-up could be the cause of the accident.

Since the release could not be stopped by intervening at the leaking point, the fire brigade decided to vent the whole content of the pallet (246 m3) by gradually opening the valves and by keeping the rack cool. The rack of the bottles was empty after four hours and the rescue operation ends at noon after the cylinder rack has been checked by an expert from the gas supply company. The residents returned to their homes and the plant's activity restarted one hour later.

The station was storing 6,000 litres of liquid hydrogen in ten tanks. Rescue services were alerted and the station's activity is interrupted. The leak was stopped by closing the valves. According to the H2Tools report (see references), a vehicle fill had depleted the high-pressure hydrogen inventory. Consequently, the compressor turned on to refill the storage by compressing 4 bar (60 psig) hydrogen from a liquid hydrogen tank up to the 380 bar (5500 psig) compressed storage tank. After running about 2 hours, a crankshaft bearing started to fail.

The release occurred on a pipeline inside a steam cracking unit located between two hydrogenation units. The gaseous mixture transported through this line (2" diameter, 30 bar, 40C) was composed of 95% hydrogen, 4% methane and 1% nitrogen. The line was located in a rack within the cold sector, at a height of 6 m. The personnel shut down the steam cracker and isolated the sector and the units cuts were sent to the flare system.

The operator detected a leak of aerosol hydrocarbons (diesel, hydrogen and hydrogen sulfide) in the diesel desulfurisation unit, causing a release of hydrogen and hydrogen sulfide at the top of the unit. The leak was located at the outlet of the desulfurization reactor, in the cooling towers. The cloud of hydrocarbon aerosols was released at a 10 m height due to the fan of the cooling tower at the origin of the leak. The cloud quickly dispersed into the air. The operator initiated the automatic shut-down of the unit and the cooling of the walls of the furnace.

A 50-litre standard hydrogen gas cylinder was temporarily placed and used in a laboratory. The hydrogen gas was used for a flame ionization detector (FID) in gas chromatography (GC) instrument. The safety relief valve on the pressure regulator blew open and released of about 340 g of hydrogen into a laboratory. The gas cloud did not ignite so there was no injury or damage. In Henriksen et al (see references) a full investigation is presented to verify the cause of leakage and estimate the gas concentration of the dispersion and gas cloud, including the modelling of a likely explosion.

The leak occurred on a 44 m vehicle of liquid hydrogen during a delivery to the unloading station of a steel plant. The truck drivers had connected the tank container to the fixed storage managed by a subcontractor, carried out a nitrogen sweep of the hose before cooling it, and were pressurizing the H2 before unloading when they saw a white cloud. The drivers closed the bottom valve of the container and the upstream and downstream valves of the heater before evacuating the area and sounding the alarm.

A hydrogen leak occurs at on the hose connection of a tank truck being loaded into an industrial gas company. Alerted by the noise, the driver of the vehicle gave the alert. Firefighters from the petrochemical platform to which the plant belongs stopped the leak by closing the manual valves on the tank. The tank, initially at 200 bar, lost only 10 bar in 3h30. The site's sensors did not activate because of the small size of the leak.

Release from a compressed storage of an optics component plant The leak was observed on the hydrogen storage consisting of 19 racks of 16 cylinders each. Rescue teams set up a security perimeter and a specialized company inspected the leak.The activity of the establishment were interrupted during the night and resumed the next morning.

During maintenance work on a gas pipeline carrying hydrogen , a worker hears a leak at about at a bridge. The operator measures an concentration of 3% of the low flammability limit at few centimetres from the leak, and no detection beyond 25 cm. The area was highly ventilated. The technicians secured the area, isolated the section five hours later and started the controlled gas release. after two additional hours the pressure had reduced to zero and they started the nitrogen inerting. The pipe was repaired the next day.