SAINT-FONS, December 22, 2025 – A major explosion at the Elkem Silicones chemical plant in Saint-Fons, a Seveso-classified site in the Lyon metropolitan area, resulted in four injured employees, three of whom are in serious condition. The incident, which occurred around 2:45 PM, prompted immediate emergency response and the implementation of a large security perimeter.
Explosion Details and Emergency Response
The explosion, attributed to a “small hydrogen reactor” in an experimental laboratory producing silicones for sealants, led to an immediate fire. Colonel Lionel Chabert, commander of rescue operations, praised the rapid and coordinated response, which included activating the ORSEC plan. Approximately 100 firefighters and 30 vehicles were mobilized to combat the blaze, which was brought under control by 5:45 PM. The injured individuals sustained burns and were transported to Édouard-Herriot Hospital. Two of the employees are still in critical condition, and a psychological support unit has been established for affected staff.
Public Safety and Traffic Disruptions
Following the explosion, the Rhône Prefecture issued confinement orders for the communes of Saint-Fons, Feyzin, Pierre-Bénite, and Vénissieux. Residents were advised to remain indoors, and those outside the perimeter were instructed not to return. Authorities confirmed that air toxicity measurements, validated by the regional environment agency, showed no risk to the public. The FR-Alert system was activated, sending notifications with safety instructions to mobile phones in the affected area. Traffic was significantly impacted, with the A7 motorway, nearby railway lines (Lyon – Vienne – Valence and Lyon-Part-Dieu – Saint-Étienne), and river traffic on the Rhône all halted. These restrictions were progressively lifted by 5:45 PM as the fire was brought under control and the immediate danger subsided. However, SNCF warned of continued disruptions on affected train lines.
Official Statements and Ongoing Investigations
Antoine Guérin, Prefect of Rhône for Security, addressed the press, confirming the nature of the explosion and the condition of the injured. Bruno Bernard, President of the Métropole de Lyon, expressed his thoughts for the victims and their families, extending gratitude to emergency services. The Elkem Silicones plant is classified as a high-threshold Seveso site, indicating a high level of industrial risk. Preliminary investigations suggest a hydrogen leak as the cause of the explosion. This incident echoes a previous fire at the same Saint-Fons site in 2016, which resulted in one fatality and significant damage to a warehouse. The full extent of the damage from the current incident is still being assessed, and investigations into the precise cause are ongoing.
Source: https://actu.fr/auvergne-rhone-alpes/saint-fons_69199/direct-grave-explosion-dans-une-usine-chimique-seveso-pres-de-lyon-plusieurs-victimes_63610713.html
