; and (B) the maximum hourly emission rate of an air pollutant that is achievable by such source after the change is higher than the maximum hourly emission rate of such air pollutant that was achievable by such source during any hour in the 10-year period immediately preceding the change. (2) Exceptions If a modification expands the capacity or production capability of a source, the modification shall not be considered to be a new source for purposes of this section if the modification is designed— (A) to reduce any air pollutant emitted by the source per unit of production; (B) to reduce any greenhouse gas emitted by the source per unit of production; or (C) to enhance or restore the safety or reliability of operations at the source. (3) Application of exceptions A modification that meets an exception described in paragraph (2) shall not be considered to be a modification for purposes of— (A) the term construction (as defined in section 169(2)) or any provision that uses that term; or (B) the term modification (as defined in section 171) or any provision that uses that term. (l) Treatment of offsets A proposed new source shall be exempt from the requirements of a proposed new source in an area designated as in nonattainment if the proposed new source emits not more than 0.5 percent of the periodic emissions inventory of the criteria pollutant for the area within which the proposed new source will be located. . (b) Rule of construction The amendments made by subsection (a) shall not treat any change as a modification for purposes of the Clean Air Act ( 42 U.S.C. 7401 et seq. ) if such change would not have been so treated as of the day before the date of enactment of this Act. 6. Treatment of pending permits (a) Preconstruction requirements Section 165(b) of the Clean Air Act ( 42 U.S.C. 7475(b) ) is amended— (1) by striking (b) The demonstration and inserting the following: (b) Exceptions (1) Maximum allowable increases The demonstration