The ISO Public Protection Classification program classifies and rates the municipal fire protection capabilities of more than 47,500 communities across the United States. Through the program, ISO collects relevant data about the quality of the community's public fire protection and then assigns it a number between one and 10, with Class 1 indicating the area has superior property fire protection and Class 10 indicating that the community's property fire protection fails to meet the minimum ISO criteria.
The ISO Public Protection Classification grading is used by most insurance companies in calculating their premiums. In general, an area with a better ISO PPC rating should have lower fire insurance rates than an area with a lower rating if all other determining factors are similar.
A community's PPC rating depends on a variety of different factors, such as its emergency communication systems. This includes the facilities for the public to report fires and for dispatching fire departments. Another factor is the quality of the local fire department, including its training, equipment and geographic deployment of its companies. The local water supply system is another determining factor, which factors in the amount of water available compared to the amount that would be needed to suppress a fire. Community efforts to reduce the risk from fires also factor into the PPC rating.