---
kind: "section"
citation: "40 C.F.R. § 51.901"
title: "40"
number: "51.901"
heading: "Applicability of part 51."
url: "https://uscodex.org/cfr/40/51.901"
---

# §51.901. Applicability of part 51.


The provisions in subparts [A](/cfr/40/part51-subpartA.md) through [W](/cfr/40/part51-subpartW.md) of part 51 apply to areas for purposes of the 8-hour NAAQS to the extent they are not inconsistent with the provisions of this subpart.


## Notes

### Source

Source: 69 FR 23996, Apr. 30, 2004, 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.