The North Carolina 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)
|
|---|
| Western Mountain Intrastate | I | III | III | III | III
|
| Eastern Mountain Intrastate | I | III | III | III | III
|
| Metropolitan Charlotte Interstate | I | II | III | III | I
|
| Northern Piedmont Intrastate | I | III | III | III | III
|
| Eastern Piedmont Intrastate | I | III | III | III | III
|
| Northern Coastal Intrastate | I | III | III | III | III
|
| Southern Coastal Intrastate | II | III | III | III | III
|
| Sandhills Intrastate | II | III | III | III | III |