Critical Explosion at Elkem Silicones Factory near Lyon Injures Four, Investigation Underway

On December 22, 2025, an explosion rocked the Elkem Silicones chemical plant located in Saint-Fons, near Lyon, causing injuries to four employees, including a chemical engineer and two technicians. One victim remains in critical condition, while three have suffered severe burns. The injured were working in a pilot workshop dedicated to experimental processes, which was installed in 2021 and is separate from the main factory facility.

Authorities and the Lyon public prosecutor have initiated an investigation into involuntary injuries leading to extended incapacitation. This inquiry is being carried out by the Organized Crime Division alongside the Departmental Directorate of Employment, Labor, and Solidarity to determine the precise cause and circumstances of the blast. Initial findings from the factory director, Jean-Pierre Lerat, suggest that the explosion was likely triggered by hydrogen emissions during a testing procedure involving the de-volatilization of hydrogenated silicone oils.

In response to the incident, approximately 100 firefighters were dispatched to extinguish the resulting fire. The emergency also prompted the closure of the nearby A7 highway, as well as rail and river transport routes. Around 1,000 residents in the vicinity were temporarily confined for their safety.

Elkem Silicones has faced previous scrutiny over safety compliance, and the factory site has a history of serious incidents, including a fatal fire in 2016. The recent explosion underscores ongoing concerns about industrial safety in the chemical valley south of Lyon. Despite being equipped with the latest safety standards, the pilot workshop’s isolation from the main site did not prevent the dangerous event.

The situation remains grave, with medical teams closely monitoring the critically injured individual. Authorities continue their investigation to clarify the causes of the explosion and to assess all contributing factors to prevent future accidents.