A petrochemical plant (chlorine derivatives) restarts its workshops after a major shutdown of 5 weeks when an explosion occurred at 14:50 in the oxychlorination unit upstream from the workshop of vinyl chloride monomer (VCM). The Emergency plan is triggered and 30 employees are confined. One of the two operators present in the vicinity is slightly wounded in the face by the heat flow of the explosion, despite wearing a protective mask (burning beneath the mask). It is supported by the plant medical staff. The operator stops the unit and discovers an ethylene leak causing a fire. The Firefighters team of the plant extinguished the fire and isolated the leak on the pipe, the Emergency plan is canceled slightly after 16 h.The rupture of a valve on a pipe of ethylene is supposed to be the cause of the accident.

The operator issues a press release and informs the neighboring communities. The administrative inspection team requires an analysis of the causes of the incident and a definition of the measures to be implemented before restarting the unit.