C.R.S. § 25-7-1205

(1) The regulatory assurances provided in section 25-7-1204 shall not apply to the following permit requirements, emission control requirements, or emission limitations: (a) Additional requirements provided under section 111 of the federal act, as defined in section 25-7-103 (12), or parts 2 and 3 of this article by any modification or reconstruction of a stationary source after the date of the voluntary agreement; (b) Emission limitations established for hazardous air pollutants identified in section 112 of the federal act; (c) Requirements established to implement Title VI and section 112 (r) of the federal act; and (d) Requirements applicable to mobile sources.