First an explosion and then a fire occurred on the condensate piping of an chlorine electrolysis plant (SEVESO upper tiers). Flames escape from the end of the pipe and spill into a 75 m open sky tank, containing the electrolysis products (water, HCL, NaOH, Na). According to the ARIA report, (see source) a maintenance operation was ongoing on the HCl furnace located nearby. Investigations conducted by the operator identified a design defect as the cause of the incident. The overflow of the guard hydrogen hydraulic system was wrongly connected to the condensate piping.

Explosion in a chemical manufacturing plant for the pharmaceutical and cosmetics industries, classified as Seveso high level, The explosion occurred in the hydrogenation reactor, when opening two buffer tanks to clean the reactor the after hydrogenation using a catalyst (ruthenium on coal). Following the explosion, the operator initiated the emergency plan, evacuated personnel and secured the area. Two operators were injured.

In a plant producing calcium carbide (CaO + 3C -> CaC2 + CO), a dust collector clogged, probably due to the failure of the cleaning device (nitrogen nozzles) which allowed the dust to build a plug.During the procedure of introducing a poker through an inspection hatch at the lower level, a small explosion occurs and a large amount of dust is ejected through the vent. The cloud containing carbon monoxide and hydrogen ignited. The fire spread to the electrical cables supplying the equipment.

In a graphite purification workshop, the cooling circuit of an electric furnace leaks, the water decomposes in contact with materials heated to a temperature of 1,800C; the gas mixture (hydrogen, air...) explodes. The carbon contained in the furnace is dispersed and ignites.

The accident originated in the isomerisation unit and propagated to the benzene saturation unit. The accident source was a mechanical rupture of one of the two compressors used to transfer hydrogen mixtures to the isomerisation unit . The rupture caused the release of a gas mixture containing hydrogen, which ignited by mixing with air, forming a jet fire. The jet fire headed was directed towards the adjacent benzene saturation unit, hitting a pressure vessel located 14 m from the release point (the jet flame could have been 30 m long in absence of obstacle).

A fire started on the brakes of a truck carrying hydrogen. Due to the risk of extension of the fire to the hydrogen, the fire brigade install an emergency area until the fire is extinguished.There has been no release of hydrogen.

Fire in a ammonia plant.The accident starts with a leak of a hydrogen-nitrogen mixture at the suction flange of a compressor. The mixture ignites on contact with air and the fire spreads to an oil bath

A liquid hydrogen leak occurs on one of the cylinders that a truck was carrying. After the leak was stopped, the vehicle was escorted by the fire brigade and taken to a laboratory for inspection.

A pallet containing 9 hydrogen cylinders is damaged during the operation of unloading the cylinders trailer by means of a forklift. A 2 mm wide crack, caused by the fork, is observed on a flexible. The fire brigade decided for an emergency and evacuation zone of 200 m. The intervention of an expert allowed to measure a remaining pressure in the pallet of 100 bar. He tightened a nut and stopped the leak after approximately 3 hours. The amount of hydrogen released was estimated at 30 m3.

A deflagration occurred inside the tank at the start of grinding operations. The tank had contained sulfuric acid. All preparatory procedures had been properly carried out: neutralisation of residual sludge with carbonate, measurement of oxygen and inflammable gases at various points. The explosion was due to the ignition of approximately 100 g of hydrogen in a dead zone of the tank, which had not been checked with detectors. The hydrogen had been produced by the corrosion of the iron of the tank by the sulfuric acid. The consequences were one dead and 2 severely injured.