The indicator makes it possible to identify areas with a particular concentration of establishments at risk of major accidents, providing useful information for land-use planning, especially for land allocation and utilization. In 2025, there are 29 municipalities with 4 or more RIR (Major Accident Risk) establishments, distributed across 12 regions: they host about one-quarter of all major accident risk establishments in Italy. The regions with the highest number of these municipalities are: Sicily (5), Lazio (4), Lombardy (4), and Piedmont (4). Among the municipalities with a high number of establishments are Ravenna with 26, Genoa with 13, followed by Trecate with 10, Naples and Venice with 9, Filago with 8, and Augusta, Anagni, Catania, and Livorno with 7 each.