---
kind: "section"
citation: "40 C.F.R. § 51.1119"
title: "40"
number: "51.1119"
heading: "Applicability."
url: "https://uscodex.org/cfr/40/51.1119"
---

# §51.1119. Applicability.


As of revocation of the 1997 ozone NAAQS on April 6, 2015, as set forth in [§ 50.10(c)](/cfr/40/50.10.md?p=c), the provisions of [subpart AA](/cfr/40/subpartAA.md) shall replace the provisions of [subpart X](/cfr/40/subpartX.md), [§§ 51.900 to 51.918](/cfr/40/51.900..51.918.md), which cease to apply except for [§ 51.907](/cfr/40/51.907.md) for the anti-backsliding purposes of [§ 51.1105(c)(2)](/cfr/40/51.1105.md?p=c-2). See [subpart X](/cfr/40/subpartX.md) [§ 51.919](/cfr/40/51.919.md).


## Notes

### Amendments

[80 FR 12314, Mar. 6, 2015]

### Source

Source: 77 FR 30170, May 21, 2012, unless otherwise noted.

### Authority

Authority: 23 U.S.C. 101; 42 U.S.C. 7401-7671q.

### Source

Source: 36 FR 22398, Nov. 25, 1971, unless otherwise noted.

### Amendments

[80 FR 12314, Mar. 6, 2015]