Pollution
Humain
Environnement
Economique

At 4:30 pm, in a shock absorber factory, steel parts were dipped into a nitric fluo bath (1-m³ tank), reserved for stainless steel parts, subsequent to a technician error in surface treatment range (automated chain). This mishap triggered a chemical reaction, which in turn led to the production of nitrous gas and hydrogen. The irritating vapours and ensuing smoke release, causing 3 workers to feel ill. The transition to manual mode in order to remove the part from the bath got underway, but given the intensity of the smoke, the operation had to be stopped and an evacuation of the workshop and entire building engaged (150 employees). All smoke outlets were opened. Equipped by fire-fighters with a breathing suit, the head of the Equipment-Safety-Environment unit accompanied by 2 fire-fighters extracted parts by using the manual electrical controls, resulting in the immediate cessation of smoke emissions. No impact on the environment was observed and the toxicological measurements were negative; however, management decided not to resume production until the next morning. The 3 ill employees were not transported to hospital; responders left the site at 8 pm. An analysis of the incident was performed by the CHSCT Workplace Safety and Hygiene Committee the following afternoon, leading to announced improvements: install a smoke detector on the chain driving the robot-activated forklift; introduce a ventilated or adapted mask in the vicinity; set up a treatment range confirmation routine; and create families of treatments on the machine.