1. a) Any pollutant for which a NAAQS has been promulgated. This includes, but is not limited to, the following:

   1. 1) PM_2.5 emissions and PM₁₀ emissions shall include gaseous emissions from a source or activity, that condense to form PM at ambient temperatures. On or after January 1, 2011, such condensable PM shall be accounted for in applicability determinations and in establishing emissions limitations for PM_2.5 and PM₁₀ in PSD permits. Compliance with emissions limitations for PM_2.5 and PM₁₀ issued prior to this date shall not be based on condensable PM unless required by the terms and conditions of the permit or the applicable implementation plan. Applicability determinations made prior to this date without accounting for condensable PM shall not be considered in violation of this Part unless the applicable implementation plan required condensable PM to be included.

   2. 2) Any pollutant identified under this subsection as a constituent or precursor for a pollutant for which a NAAQS has been promulgated. Precursors for purposes of this Part are the following:

      1. A) VOM and NO_X are precursors to ozone in all attainment and unclassifiable areas.
      2. B) SO₂ is a precursor to PM_2.5 in all attainment and unclassifiable areas.
      3. C) NO_X are presumed to be precursors to PM_2.5 in all attainment and unclassifiable areas, unless the State demonstrates to the satisfaction of USEPA or USEPA demonstrates that emissions of NO_X from sources in a specific area are not a significant contributor to that area's ambient PM_2.5 concentrations.
      4. D) VOM are presumed not to be precursors to PM_2.5 in any attainment or unclassifiable area, unless the State demonstrates to the satisfaction of USEPA or USEPA demonstrates that emissions of VOM from sources in a specific area are a significant contributor to that area's ambient PM_2.5 concentrations;
2. b) Any pollutant that is subject to any standard promulgated under section 111 of the CAA (42 USC 7401);
3. c) Any Class I or II substance subject to a standard promulgated under or established by title VI of the CAA (42 USC 7671, et seq.);
4. d) Any pollutant that otherwise is subject to regulation, as defined in Section 204.700.
5. e) Notwithstanding subsections (a) through (d), the term "regulated NSR pollutant" shall not include any or all hazardous air pollutants either listed in section 112(b)(1) of the CAA (42 USC 7412(b)(1)) or added to the list under CAA section 112(b)(2) or (b)(3), or substances listed under CAA section 112(r)(3) and that have not been delisted under CAA section 112(b)(3) or (r), unless the listed hazardous air pollutant is also regulated as a constituent or precursor of a pollutant listed under CAA section 108 (42 USC 7408).

"Regulated NSR pollutant" means the following: