Employees were trying to open the manhole cover (600 mm diameter) of a hydrofluoric acid tank with a grinder, when an explosion occurred. The explosion was probably caused by the presence of hydrogen formed by the acid attack of the metal.

The fire took place during maintenance works in one out of the three gas extractors of the coke process line. Main cause was displacement of a flange which allowed the entrance of flammable mixture gas (methane, carbon monoxide hydrogen and benzene) which ignited probably due to electrostatic spark. According to the ARIA report (see references) total quantity of gas released was 62 400 m, consisting of 11,7 t CH4, 0,98 t C6H6, 5,1 t CO and 3,4 t H2.During maintenance works, gas extractors were usually isolated and kept under continuous flow of N2.

Two workers were asked to change the piping and support of a feed line into an intermediate storage vessel for hydrochloric acid. The explosion occurred when they opened the gas line and started grinding on the support, The flame propagated back into the tank, causing a second explosion inside. The explosion was caused by the unexpected presence of a considerable amount of hydrogen in the tank. According tot the eMARS and ARIA report (see references) , the hydrogen was formed in a reaction of metal powder traces and the hydrochloric acid, and must have accumulated over a period of two months.

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).

The explosion occurred in a copper electroplating plant test furnace when starting the operation of copper plating. EVENT DETAILS A tinned copper pipe had been placed inside another copper pipe and lined with pellets. Inside the furnace, the pellets were intended to adhere to the outer surface of the smaller tinned copper pipe under hydrogen atmosphere. The test was the third in the series. A vacuum was created inside the furnace, and an indicator light showed that a vacuum had been successfully generated.

The accident occurred in the Reactor 6 used to carry out the hydrogenation of a pharmaceutical intermediate.The operation of the plant was organized in two shifts. Since the hydrogenation at Reactor 6 would have taken at least 30 hours, it was not possible to complete the reaction during a single shift. The reaction was commenced at 8:00 a.m.

The accident took place in a tank-type pressurised separator on the synthesis gas line of an ammonia production plant. The pressurised separator operates at nominal values of 25 bar and 5C. It contains a mixture of hydrogen and nitrogen (75%/25%). It is located slightly upstream of the synthesis gas compressor (on the low pressure side) that was shut down. The connector connecting the separator to its level measuring instrument is located outside, near the building containing the compressors.

In a lube oil plant of a refinery, during the isomerisation of wax, the high pressure reactor ruptured, releasing gas composed by 70 % of hydrogen and 30 % of gaseous hydrocarbons (methane, ethane and others). The release gas was ignited and a fire developed in the plant area where operators and engineers were working. After the shut-down of the plant, 4 on-site firemen brigade provided to extinguish the fire. No people were injured.

on a Sunday morning, in a ceramic factory, a leak on a 100 m tank containing 370 kg of hydrogen caused an explosion. The generated pressure wave causes significant damage to exterior buildings (broken windows, fire starts); a fragment of the tank was found several hundred meters from the place of the explosion. The human toll shows 23 people from the public who were slightly injured. A fire broke out soon after on the site and threatened storage of acetylene and hydrogen fluoride.

A pipe failed, probably due to material failure, and the plant was automatically put in hot stand-by (feed and energy supply automatically cut out). The plant was gradually cooled down. After about half an hour, for reasons not yet clarified, a fire started at the outlet of the alkylation reactor. The fire was extinguished by intervention of the operators, plant fire brigade and local fire brigade. The fire water was collected in a basin and disposed of after treatment in the biological waste water treatment plant of the establishment.