what rules must these factories follow?

Fertilizer factories, oil or chemical storage sites, or wastewater treatment plants. In France, many sites are classified as high risk, they are called Seveso. These are factories in which there are hazardous substances in large quantities, which present a danger to human health and the environment, and which could be the source of explosions and fires. In France, there are 1,301 Seveso sites, including 692 so-called high threshold, that is to say at very high risk.

These companies have the obligation to control the danger related to their activity. They must, for example, identify and declare hazardous substances, carry out hazard studies, draw up accident prevention plans, and inform local residents and personnel of the risks. Indeed, Seveso sites are often located close to dwellings.