In France, according to the directive n° 96/82 of the Council of the December 9th 1996 and the decree of the May 10th 2000], a major accident is:

• an event such as an emission (of gas, radioactive product, disease-causing agent, pollutant), a fire or a Explosion of major importance,
• resulting from uncontrolled developments which have occurred during the exploitation of an establishment,
• involving for the human health, inside or outside the establishment, and/or for the environment a serious, immediate or differed danger,
• and utilizing one or more dangerous substances.

See too

• Accident

• Catastrophe
• Risk
• Emergency plan