20 t of acrolein was released into the Rhone River. The manufacturing unit was undergoing its annual shutdown at the time and the neutralisation ponds (2 x 250 m³) were under repair. For the last four months, the tank cleaning water had been directed into a 15 m³ neutralisation channel and released into the RHONE without control. During a rinsing operation, an operator accidentally emptied an full railcar (No. poorly transcribed). The employee noticed the anomaly an hour later, and unsuccessfully attempted to contact his supervisor by telephone. Unaware of the operating instructions and the possible consequences, he allowed the drainage operation to continue. The plant’s management was informed only 36 hours after the accident.
For a period of 8 days, 367 t of dead fish were collected along the river over 90 km (5 departments). A safety program was set up to prevent swimming along the river, to monitor the reservoirs and wells fed by the RHONE and the drinking water distribution system.
This pollution, as well as other accidents, was one of the 1st safety studies conducted in France