StacksVerified U.S. regulatory reference

40 CFR §51.1119

Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗
As of revocation of the 1997 ozone NAAQS on April 6, 2015, as set forth in § 50.10(c), the provisions of subpart AA shall replace the provisions of subpart X, §§ 51.900 to 51.918, which cease to apply except for § 51.907 for the anti-backsliding purposes of § 51.1105(c)(2). See subpart X § 51.919.