U.S. Code of Federal Regulations
Regulations most recently checked for updates: Aug 27, 2025
The Hawaii plan was evaluated on the basis of the following classifications:
| Air quality control region | Pollutant | ||||
|---|---|---|---|---|---|
| Particulate matter | Sulfur oxides | Nitrogen dioxide | Carbon monoxide | Photochemical oxidants (hydrocarbons) | |
| State of Hawaii | II | III | III | III | III |
