U.S. Code of Federal Regulations
Regulations most recently checked for updates: Oct 07, 2025
The Rhode Island plan was evaluated on the basis of the following classifications:
Air quality control region | Pollutant | ||||
---|---|---|---|---|---|
Particulate matter | Sulfur oxides | Nitrogen dioxide | Carbon monoxide | Ozone | |
Metropolitan Providence Interstate | I | I | III | I | I |