The event occurred in an atmospheric pressure tank storing effluents. The plant was in the production phase. The head of the overfill prevention valve located at the top of the tank was thrown a distance of 77 m. The tanks shell was deformed (curved downward) but not leaking. Employees noted a noise similar to the opening of a valve, and a low-pressure alarm in the tank appeared in the control room, despite the fact that the level and temperature were normal.

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.

An accident occurred prior to the performance of a hydrogen-oxygen balloon demonstration, seriously injuring the demonstrator, who suffered painful second-degree burns to his right forearm and had to be taken to the hospital. The paramedics feared that grave respiratory damage (due to flame inhalation) might have occurred.To prepare for the demonstration, the demonstrator had transported 15 balloons (pre-filled with a hydrogen-oxygen gas mixture) in a large, black polyethylene garbage bag. During the demonstration set-up he opened the bag to remove a single balloon for stringing and floating.