At least one person was injured in an explosion at a theatre building. The investigation concluded that the accident has been caused by hydrogen entering the sprinkler room from the sprinkler piping, during maintenance of the building's sprinkler system. Together with indoor air, it formed a flammable mix of hydrogen gas and air. it is known that hydrogen forms in pipes due to corrosion of the pipe internal zinc coating by oxygen and water. The investigation could not identify the exact cause of the ignition.

The fire occurred on a flange of a hydrogen supply line to a desulfurization reactor unit of diesel, which leaked and ignited (30 cm flame) The leak was stopped by isolating the part of line affected, by closing the upstream and downstream valves , and shutting down the reactor.

In a plant manufacturing chlorate products, a hydrogen leak occurred via the water drainage outlet onto the factory floor. Pressure in the hydrogen line increased because the hydrogen pipes were filled with water. The situation was rectified by shutting down the process, draining the pipes and by redirecting the hydrogen flow.CAUSE: The root cause may be deemed to be insufficient level of automation because a selection permitting human error had been left in the process.

Following the breakdown of a piston rod, a mixture of hydrogen and light hydrocarbons was released from the fresh hydrogen compressor of an oil refinery. The rod broke down because of stress corrosion. The stress exerted on the rod was significantly increased by the looseness of the piston fixing point.The gas mixture ignited, also igniting the lubricating oil and other items in the room. Some 1,500 kg of hydrogen gas and a few hundred litres of lubricating oil were estimated to have been burned.

At a soaking facility of an industrial plant in the metallurgy sector, the pipeline between a supply tank and a feed pump became clogged and the autoclave only received sporadic feed. Problems had been experienced with the feed over several days. The pipeline was flushed with water to little avail. Because no feed was received in the autoclave, no oxygen could enter to maintain the pressure of the autoclave normally. The blockage was quickly cleared, as a result of which a large quantity of feed, and with it solids that were contained in the blockage, entered the autoclave.

The reduction stage of the powder production process of a chemical plant had been shut down, and the buffer tank of the line had been drained on the preceding day. After the shutdown, the batch to be reduced was normally processed in the autoclave and the process was duly acknowledged. The sequence opened the autoclave degassing operation via the cyclone up to the roof, as a result of which the pressure inside the autoclave started to fall. Soon after that, an explosion occurred in the buffer tank downstream of the autoclave and at the gas scrubber.

An explosion occurred in the glass components of a reactor at a pharmaceutical plant during a batch process. At the time of the accident, the reactor was being hydrogenated. As a result of the explosion, the upper part of the glass components broke, some of the suspended ceiling boards fell off and ceiling light cover glasses were splintered, and one of the inner windows of the explosion wall two metres from the site broke. The accident did not result in any personal injuries.

An explosion occurred in the hydrogen washing tower of a chlorate plant caused by the breaking of the rupture diaphragms on the tower cover. The discharged hydrogen ignited, causing a minor leakage of hydrochloric acid in the hydrochloric acid top container above it and the related pipes.The explosion was preceded by an abrupt reduction in the electrolysis flow resulting from a rectifier malfunction and operation at low flow density. This caused a significant increase in the oxygen level in the hydrogen gas.

Two mechanic workers had picked up a work permit for the removal of filters from a hydrogen line. An operator also visited the scene and answered the mechanics question as to whether the line should be de-pressurised and that it indeed should be so. The mechanics replaced the low-pressure side (4 bar) suction strainer at which point they noticed that there was pressure inside the pipe, which they released into the piping leading to the flare. In the afternoon, they carried out a similar filter replacement on the high-pressure side (34 bar).

Hydrogen ignition during the (illegal) filling of a balloon.Two men had decided to fill in a weather balloon with hydrogen in a storeroom located in the basement of a block of flats. Their idea was to attach a video camera to the balloon for the purpose of taking aerial photos. To fill in the balloon, the men had purchased a 20 kg hydrogen bottle and a valve and constructed a special mouthpiece for the purpose. They had tried filling a similar balloon previously. Then, they did not experience any problems in filling the balloon and had left the balloon in the basement to let it empty.