In a chemical plant, a fire broke out at around 10 am in the 30 m² retention system connected to a column for scrubbing the gases extracted from “phosgene” installations. Two fire detectors were activated: one in an equipment room located in the hall and the other connected to the hall’s ventilation system. By contrast, no detection system was connected to the retention system. Water curtains were actuated at 10.09 am.

The establishment activated its internal emergency plan and the staff gathered together at the various specified meeting points. The town halls of Blyes and Saint-Vulbas as well as the neighbouring establishments were informed of the fire at 10.20 am. The in-house emergency response teams contained the fire within 10 min, and then continued cooling the column. The retention system contained a column filled with 13 m³ of soda, 2 pumps compliant with ATEX regulations and three tanks, 1 for the soda reserve for the neutralisation installation and 2 other 1 and 3 m³ tanks for the solvents (toluene-ethanol, THF). Drained a few days earlier, the retention system was filled with water following rain over the weekend (10-15 cm). The 5 am team noted that the 3 m³ capacity was full and gave instructions not to unload anything into it. Water had been accidentally introduced into the solvent collection system during a cleaning operation. The water recovered in the 1 m³ tank had been directed by gravity to the 3 m³ tank and by piston effect had overflowed into the retention system. The operating guidelines had not been formalised. Two sub-contracted employees had ground and welded above the retention system with no continuous monitoring of the work by a security officer. No prior inspection had been carried out in the area concerned by the hot work permit before this permit had been issued. No indications were marked on the tanks regarding the hazards of the products stored. There were no victims. The site resumed its activity at the end of the day. A formal notification order was recommended. During the visit on 05/10, the inspection authorities for classified facilities noted discrepancies and drew up a report establishing the facts.