PM10 and PM2.5

Section 243 Section 243.120  PM 10 and PM 2.5 a)         1987 Primary and Secondary 24-Hour NAAQS for PM 10 1)         The level of the 1987 primary and secondary 24-hour NAAQS for PM 10 is 150 μg/m 3 , 24-hour average concentration.  The 1987 primary and secondary NAAQS for PM 10 is attained when the expected number of days per calendar year with a 24-hour average concentration above 150 μg/m 3 , as determined in accordance with appendix K to 40 CFR 50, incorporated by reference in Section 243.108, is equal to or less than one. 2)         This subsection (a)(2) corresponds with 40 CFR 50.6(b), a provision marked "reserved" by USEPA.  This statement maintains structural consistency with the corresponding federal regulation. 3)         For the purpose of determining attainment of the 1987 primary and secondary 24-hour NAAQS for PM 10 , particulate matter must be measured in the ambient air as PM 10 by a method that fulfills either of the following requirements: A)        An FRM based on appendix J to 40 CFR 50, incorporated by reference in Section 243.108, and designated by USEPA and listed in List of Designated Methods, incorporated by reference in Section 243.108; or B)        An FEM designated by USEPA and listed in List of Designated Methods, incorporated by reference in Section 243.108. BOARD NOTE:  This subsection (a) is derived from 40 CFR 50.6. b)         1997 Secondary Annual Average and Primary and Secondary 24-Hour NAAQS for PM 2.5 1)         The 1997 secondary annual average NAAQS for PM 2.5 is 15.0 μg/m 3 , annual arithmetic mean concentration, and the 1997 primary and secondary 24-hour NAAQS for PM 2.5 is 65 μg/m 3 , 24-hour average concentration, measured in the ambient air as PM 2.5 by a method that fulfills either of the following requirements: A)        An FRM based on appendix L of 40 CFR 50, incorporated by reference in Section 243.108, and designated by USEPA and listed in the List of Designated Methods, incorporated by reference in Section 243.108; or B)        An FEM designated by USEPA and listed in the List of Designated Methods, incorporated by reference in Section 243.108. 2)         The 1997 secondary annual average NAAQS for PM 2.5 is met when the annual arithmetic mean concentration, as determined in accordance with appendix N of 40 CFR 50, incorporated by reference in Section 243.108, is less than or equal to 15.0 μg/m 3 . 3)         The 1997 primary and secondary 24-hour NAAQS for PM 2.5 is met when the 98 th percentile 24-hour concentration, as determined in accordance with appendix N of 40 CFR 50, incorporated by reference in Section 243.108, is less than or equal to 65 μg/m 3 . BOARD NOTE:  This subsection (b) is derived from 40 CFR 50.7. c)         2006 Secondary Annual Average and Primary and Secondary 24-Hour NAAQS for PM 2.5 1)         The 2006 secondary annual average NAAQS for PM 2.5 is 15.0 μg/m 3 , annual arithmetic mean concentration, and the 2006 primary and secondary 24-hour NAAQS for PM 2.5 is 35 μg/m 3 , 24-hour average concentration, measured in the ambient air as PM 2.5 by a method that fulfills either of the following requirements: A)        An FRM based on appendix L of 40 CFR 50, incorporated by reference in Section 243.108, and designated by USEPA and listed in the List of Designated Methods, incorporated by reference in Section 243.108; or B)        An FEM designated by USEPA and listed in the List of Designated Methods, incorporated by reference in Section 243.108. 2)         The 2006 secondary annual average NAAQS for PM 2.5 is met when the annual arithmetic mean concentration, as determined in accordance with appendix N of 40 CFR 50, incorporated by reference in Section 243.108, is less than or equal to 15.0 μg/m 3 . 3)         The 2006 primary and secondary 24-hour NAAQS for PM 2.5 is met when the 98 th percentile 24-hour concentration, as determined in accordance with appendix N of 40 CFR 50, incorporated by reference in Section 243.108, is less than or equal to 35 μg/m 3 . BOARD NOTE:  This subsection (c) is derived from 40 CFR 50.13. d)         2012 Primary Annual Average and 24-Hour NAAQS for PM 2.5 1)         The 2012 primary annual average NAAQS for PM 2.5 is 12.0 µg/m 3 annual arithmetic mean concentration, and the 2012 primary 24-hour NAAQS for PM 2.5 is 35 µg/m 3 24-hour average concentration, measured in the ambient air as PM 2.5 by a method that fulfills either of the following requirements: A)        An FRM based on appendix L of 40 CFR 50, incorporated by reference in Section 243.108, and designated by USEPA and listed in List of Designated Methods, incorporated by reference in Section 243.108; or B)        An FEM designated by USEPA and listed in List of Designated Methods, incorporated by reference in Section 243.108. 2)         The 2012 primary annual NAAQS for PM 2.5 is met when the annual arithmetic mean concentration, as determined in accordance with appendix N of 40 CFR 50, incorporated by reference in Section 243.108, is less than or equal to 12.0 µg/m 3 . 3)         The 2012 primary 24-hour NAAQS for PM 2.5 is met when the 98 th percentile 24-hour concentration, as determined in accordance with appendix N of 40 CFR 50, incorporated by reference in Section 243.108, is less than or equal to 35 µg/m 3 . BOARD NOTE:  This subsection (d) is derived from 40 CFR 50.18. e)         2024 Primary Annual Average and 24-Hour NAAQS for PM 2.5 1)         The national primary ambient air quality standards for PM 2.5 are 9.0 micrograms per cubic meter (µg/m 3 ) annual arithmetic mean concentration and 35 µg/m 3 24-hour average concentration measured in the ambient air as PM 2.5 (particles with an aerodynamic diameter less than or equal to a nominal 2.5 micrometers) by either: A)        An FRM based on appendix L of 40 CFR 50, incorporated by reference in Section 243.108, and designated by USEPA and listed in List of Designated Methods, incorporated by reference in Section 243.108; or B)        An FEM designated by USEPA and listed in List of Designated Methods, incorporated by reference in Section 243.108. 2)         The primary annual PM 2.5 standard is met when the annual arithmetic mean concentration, as determined in accordance with appendix N of 40 CFR 50, incorporated by reference in Section 243.108, is less than or equal to 9.0 µg/m 3 . 3)         The primary 24-hour PM 2.5 standard is met when the 98 th percentile 24-hour concentration, as determined in accordance with appendix N of 40 CFR 50, incorporated by reference in Section 243.108, is less than or equal to 35 µg/m 3 . BOARD NOTE:  This subsection (e) is derived from 40 CFR 50.20.