In a refinery, a fire occurred at a new reactor for the vacuum distillate hydro-desulfurization unit. Internal gas (hydrogen, hydrocarbon, etc.) blew from a flange of upper piping in the reactor. It ignited producing 0.5-2 meters high flames.

A triangle flask exploded during a science-class experiment where diluted hydrochloric acid was made to react with zinc to generate hydrogen, at a junior high school. Injures were caused by glass debris flown, five very lightly injured pupils were sent to hospital. Probably hydrogen entered in contact with oxygen because of a wrong experiment procedure, resulting in ignition and explosion.

Electric spark ignited hydrogen in a captive advertising balloon.

Static electricity ignited hydrogen in a rising advertising balloon.

Ignition of hydrogen produced by washing slag in a tank for chlorosulfonic acid.

Explosion due to injection of hydrogen into a furnace containing residual air.

Hydrogen gas leaking from drain pipes in a hydrodesulfurization plant: There was a hydrodesulfurisation plant which had a recycle hydrogen compressor fitted with a suction rectifier. Hydrogen gas gushed out through a hole made by corrosion at the drain pipe on the suction rectifier. The process condition (45C and 3.7Mpa) made atmosphere causing hydrogen sulfide-ammonia corrosion in the drain pipe which consisted of about 10m horizontal parts and an upward outlet. This upward outlet made it impossible to drain out completely. Furthermore, steam insulation also contributed to the corrosion.

When waste alkali solution was taken out of dumper trucks into a waste liquid storage tank, a reaction occurred in the tank. As a result, the solution in the tank foamed over it, and reached an incinerator burning waste wood, when all the waste solution got in flames. The cause of the incident was the waste alkali solution with heavier specific gravity than water, which sank in a mass and came into contact with aluminum powder that had accumulated at the bottom the tank. This resulted in generation of hydrogen gas, which was ignited by fire at the incinerator.

Flask explosion due to hydrogen in the science class.

The nuclear plant was a boiling-water reactor with an output of 0.54 million kW. The component affected was a steam piping (inside diameter: 15 cm; thickness: 1.1 cm) of a heat exchanger used for removing residual heat from the reactor. The piping was broken during a test of a high pressure core injection system for cooling water provided for an emergency core cooling system. The incident resulted in a leakage of radioactive gases. The part of the piping broken was located on the 2nd floor of the building, but there were no workers there.