40 CFR § 51.1313
Section 182(f) NOX exemption provisions
June 9, 2020
(a) A person or a state may petition the Administrator for an exemption from NOX obligations under CAA section 182(f) for any area designated nonattainment for a specific ozone NAAQS and for any area in a CAA section 184 ozone transport region.
(b) The petition must contain adequate documentation that the criteria in CAA section 182(f) are met.
(c) A CAA section 182(f) NOX exemption granted for a prior ozone NAAQS does not relieve the area from any NOX obligations under CAA section 182(f) for a current ozone NAAQS.
[83 FR 63033, Dec. 6, 2018]