1. Are there any aggregation rules?

The amended arrêté du 10 mai 2000 stipulates that the risk analysis must describe the scenarios that lead to hazardous phenomena and potential accidents, and that none should be ignored or excluded without explicit prior justification. The effect of this decree has been to significantly increase the number of scenarios presented in hazard studies. At the same time, the former circular of September 29, 2005 (reiterated in the circular of May 10, 2010) introduced conditions for the acceptability of a site based on the number of MMR rank 2 hazardous phenomena.

In order to apply this rule, manufacturers are proposing that certain scenarios be grouped...