40 CFR § 52.421 - Classification of regions.

§ 52.421 Classification of regions.

The Delaware 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)
Metropolitan Philadelphia Interstate I I III I I
Southern Delaware Intrastate III III III III III
[37 FR 10856, May 31, 1972, as amended at 39 FR 16345, May 8, 1974]