1. Reasons for creating the registration system

Facilities presenting a risk to the environment are listed in the ICPE (Installations Classées pour la Protection de l'Environnement) nomenclature, according to their activity or the use of certain toxic, flammable or explosive substances... For a long time, there were two main categories of facility in the nomenclature:

• activities subject to prefectoral authorization (A), including facilities presenting major technological risks – for which authorization gives rise to public utility easements –;

• activities subject to declaration (D).

Given the small number of inspectors (figure 1...