In a chemical plant, an electrical fire occurred on a cable tray of the “small fluorinated organic products” unit; it was detected and extinguished by plant technicians using fire extinguishers, after observing a loss of information on the unit’s display screens. The emergency services were alerted. Upon arriving at the site, they noted that the Special Intervention Plan (SIP) siren was not operable.
A few minutes later, a hydrochloric acid (HCl) leak occurred on the unit’s hydrolysis column, resulting in the formation of a white cloud of hydrogen chloride, which escaped from the top of the tower housing 24 m high; hence, 6 m³ of gaseous acid were lost. Measurements taken at ground level inside and outside the site however, shortly after the event by emergency services, revealed no abnormal concentrations.
Property damage only concerned the cable tray destroyed by the fire. Two production units of the plant were stopped. One restarted quickly, but the damaged unit remained shut down for over a week. A press release was issued regarding the accident.
The cause of the electrical fire was not established. Concerning the acid leak, the operator assumed that the shutdown of valves and equipment due to the power loss caused by the fire had triggered a sudden increase in pressure or a thermal shock in the hydrolysis column, resulting in a joint or valve leak. Moreover, the HCl detector inside the tower cabin malfunctioned, likely due to a power failure.