40 CFR § 51.1119 - Applicability.

---
identifier: "/us/cfr/t40/s51.1119"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "40 CFR § 51.1119 - Applicability."
title_number: 40
title_name: "Protection of Environment"
section_number: "51.1119"
section_name: "Applicability."
chapter_name: "ENVIRONMENTAL PROTECTION AGENCY"
subchapter_number: "C"
subchapter_name: "AIR PROGRAMS"
part_number: "51"
part_name: "REQUIREMENTS FOR PREPARATION, ADOPTION, AND SUBMITTAL OF IMPLEMENTATION PLANS"
positive_law: false
currency: "2026-04-05"
last_updated: "2026-04-05"
format_version: "1.1.0"
generator: "[email protected]"
authority: "23 U.S.C. 101; 42 U.S.C. 7401-7671q."
regulatory_source: "36 FR 22398, Nov. 25, 1971, unless otherwise noted."
cfr_part: "51"
---


# 51.1119 Applicability.

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.

[80 FR 12314, Mar. 6, 2015]