In a chemical plant producing organometallic salts, an explosion occurred in a reactor during chromium octoate batch manufacturing. The blast was followed by the formation of a 2 to 3 m high column of fire above the roof and a small emission of smoke. The roof was partially split open due to the explosion or projection of the distillation column downstream of the reactor. Debris was found 100 m from the building involved. A safety perimeter of 350 m was set up, and 120 employees from companies in the sector were evacuated at 4 am.

The human toll was 2 injured, 1 employee fortunately protected by his overalls, sprayed with weak acid and 1 firefighter who fractured his collarbone following a fall during the intervention; they were hospitalised for less than 24 hours. 7 other employees, who were admitted to hospital for observation, showed no evidence of problems. The production of a nearby slaughter house was blocked while analyses demonstrating no chromium VI contamination were being carried out, as employees had effectively highlighted the passage of a green coloured cloud over the site.

The explosion occurred when work resumed that Monday morning after the weekend shutdown, while loading reagents into a 10 m³ reactor. At the time of the explosion, the reactor contained 750 kg of water in which 600 kg of chromium trioxide in ball form were dissolved (to form chromic acid). 2-ethylhexanoïc acid was being loaded (250 kg added at the time of the explosion from the 3,000 kg planned). Witnesses would have noticed a whistling noise and observed smoke at the junction between the reactor and the distillation column a little before the accident. A legal enquiry was carried out. The site’s 17 employees were placed on technical unemployment for 3 weeks and the operating losses were assessed at 0.05 million euros/day.