The accident occurred during the first phase of the batch synthesis of tricarbonyl compound (methylcyclopentadienyl) manganese (TMCM), while the reaction mixture in the reactor consisted of more than 0.5 t of sodium and organic compounds. Reaction runaway with hydrogen production caused a large increase in pressure and temperature leading to a rupture of the reactor (above 100 bar). The ignition of the released flammable cloud led to the formation of a fireball and generated a large heat flux.

A deflagration occurred at a chemical plant during a synthesis operation involving sodium tri-acetoxy-borohydride inside a 5,300-litre reactor. Around 5:30 pm, the technician observed that the acetic acid intake pipe was blocked. After opening the manhole with a wooden pole, the shop foreman dropped the stalactite of solidified acetic acid in the reactor: the resulting blast severely burned the foremans face.The event was caused by ignition of the hydrogen produced from the dropped quantity of acetic acid.

A potentially explosive situation was reported by safety inspectors at a nuclear waste tank. The waste slurry had formed a thick crust which was trapping hydrogen being continuously generated underneath. The tank has uncertain chemistry and contents.According to the New Scientist article (see references) four million litres of waste "have been behaving mysteriously inside the underground storage tank. Every few months the tank burps releasing a burst of hydrogen and nitrous oxide."Calculation estimated a potential for an explosion equivalent to 230 kilos of TNT.

A series of explosions at an oil refinery reformer unit caused by a rupture to an 8 inch naphtha and hydrogen feed pipe. The large number of injuries was due to the close proximity of a construction crew working in the area. Two were declared dead at the scene and a further two later in hospital.The ensuing fires were quickly contained and extinguished, but caused offsite traffic within several blocks to be stopped.As a precautionary measure, a second reformer unit was shutdown pending the investigation. Fire officials cited higher than normal line pressures just before the blast.

An explosion occurred caused by a leak of hydrogen from a reactor on a fertilizer plant. The blast hurled the head of a hydrogen gas converter 150m and sent it crashing through reinforced-concrete beams in a warehouse roof. The factory supplied hydrochloric acid, ammonium sulphate and urea to other plants. Damage estimated at approximately, 1 million. (1985).

A fire occurred in a hydrogen and catalyst loading lines of heavy oil unit. The most likely cause was that a hydrogen purge pipeline failure allowing hydrogen to escape. This mixed with hot oil bringing the temperature to approximately 825 degrees F (441 degrees C), i.e. above the auto-ignition temperature.