The boat was performing a drive test when one of the 280 lead gel batteries exploded and took fire. The local fire brigade was able to extinguish the fire but the above deck section of the boat was extensively damaged. According to Volger and to Wannemacher (see references), the automatic fire-alarm system of the hydrogen storage and the fuel cells were "brought in a safe state" and did not suffered any damage.

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 pressure vessel in a chlorine separation system exploded after the corrosion of the steel process equipment allowed chlorine and hydrogen to mix and form a volatile mixture. The chlorine receiving tank ruptured violently into five pieces (three large ones and two smaller) causing considerable damage to nearby equipment. The appearance of the pieces confirmed that a the tank had failed by a rapid brittle fracture. The large size of the pieces and the degree of external damage implied a vapour-phase explosion rather than a more energetic liquid-explosion.

The failure of a high pressure hydrogen-based synthetic gas feed line to the ammonia converter produced a sudden explosion followed by a severe fire. One of the operators was fatally injured. The failure of the feed line was characterized by a sudden rupture. There was no leakage prior to rupture. Portions of the piping shattered in a brittle fracture, which was produced due to a severe hydrogen attack. Extensive blisters were observed on the inside surface which failed.The initial crack probably originated at one of two small nozzles provided for temperature measurements.

The event occurred at the chlorine drying towers. The towers, made of PVC, exploded suddenly and violently in a mercury amalgam cell chlorine plant. Because of failure of the electrical power system a circuit breaker tripped out the mercury pumps stopped and the steel bottom plates in the cells became exposed. The alarm did not work since both the AC power supply to the mercury pumps and that for the alarm system were taken from the same source. Meanwhile the DC power and brine supply to the cells were not interrupted.

The explosion took place in the hydrogen gasometer. The bell in the gasometer was lifted 15-20 m straight up and cracked. The cover fell down on the pipe bridge besides the gasometer. The cylindrical part of the bell fell down into the gasometer basin. The reason for the explosion was transportation of oxygen into the hydrogen gasometer. This was due to poor drainage, and corresponding overpressure in the oxygen flow line. No persons were injured. The hydrogen gasometer was destroyed, and there was also considerable damage to the 02 and N2 gasometers.

The cracking happened in an ammonia plant, started up in 1970, on the pipe leading hot synthesis gas from the synthesis convertor to the first heat exchanger. This pipe was affected by six cracks and consequent leakages, along a time span from 1978 to 1982. Following each cracking, repair/re-welding was performed. Before the last cracking, part of the pipe was replaced with a new piece. All the crack occurred at a approximately 90 degrees bend of the pipe. No serious fires occurred.

The event occurred during welding works which ignited accidentally released hydrogen. The plant had been partially shut down for repairing works to a pipe affected by internal cracks. The repairing schedule foresaw grinding and external welding of the defective parts. Despite the purging phase to guarantee drying of the pipe section, further water leakage was hindering the work, so that additional measures was taken, also to avoid too much gas waste. The hydrogen entered the system by a leaking valve, undetected at the time of job preparation and during subsequent checks.

The accident happened in a refinery unit, constructed ten years before. A pigtail ruptured in a steam reformer for the production of hydrogen, and caused a major fire, which destroyed most of the tubes (54) in one quadrant of the large steam-methane reformer furnace. No personnel was hurt. Main causes were bad weld quality and shortening of pigtails over the life of the plant, which significantly increased the cyclic stress at the root of the weld from thermal expansion and tube bowing.

The accident happened in an anhydrous ammonia plant, commissioned in March 1977. Hydrogen accumulated inside a Benfield solution (hot potassium) storage tank and was ignited by a static charge, which caused the explosion.Mechanism by which hydrogen may have entered the storage tank are described in the paper (block valve leakage, H2 solubility in Benfield solution, etc.).The explosion sent the tank roof and sidewalls some 37m into the air, expelling an estimated amount of 114 m3 of solution into the process area.