§ 51.900 Definitions.

The following definitions apply for purposes of this subpart. Any term not defined herein shall have the meaning as defined in 40 CFR 51.100.

(a) 1-hour NAAQS means the 1-hour ozone national ambient air quality standards codified at 40 CFR 50.9.

(b) 8-hour NAAQS means the 8-hour ozone national ambient air quality standards codified at 40 CFR 50.10.

(c) 1-hour ozone design value is the 1-hour ozone concentration calculated according to 40 CFR part 50, Appendix H and the interpretation methodology issued by the Administrator most recently before the date of the enactment of the CAA Amendments of 1990.

(d) 8-Hour ozone design value is the 8-hour ozone concentration calculated according to 40 CFR part 50, appendix I.

(e) CAA means the Clean Air Act as codified at 42 U.S.C. 7401–7671q (2003).

(f) Applicable requirements means for an area the following requirements to the extent such requirements apply or applied to the area for the area's classification under section 181(a)(1) of the CAA for the 1-hour NAAQS at designation for the 8-hour NAAQS: