At 08:51 am. “coking plant gas” (combination of 65% hydrogen, 3-6% carbon monoxide and 20-25% methane) was released in a foundry during maintenance works. The leak, estimated 125 to 250 kg of gas, was followed by a violent explosion, which caused the death of 3 subcontractors, 39 injured, among whose 13 seriously burned and material damage.

The maintenance works were supposed to be done on the water piping network, which necessitated a “gas stop”. This procedure, which is carried out very seldom because it might damage the oven, takes about 10 h. Therefore, employees decided to do some works on gas pipe network and some other cleaning works in the meantime. Safety checks were thus carried out on the gasometer (to store coke oven gas) that had been repaired the previous week. The explosion occurred when subcontactors were replacing a measuring diaphragm by a blind flange on the gas pipeline (not or badly inerted).

The inspection underlined the lack of safety culture of the company, the absence of written procedures for inerting the gas line, the absence of coordination the different contractors and plant employees…