---
kind: "section"
citation: "40 C.F.R. § 97.181"
title: "40"
number: "97.181"
heading: "General."
url: "https://uscodex.org/cfr/40/97.181"
---

# §97.181. General.

- (a) Except as otherwise provided in [§§ 97.101 through 97.104](/cfr/40/97.101..97.104.md), [§§ 97.106 through 97.108](/cfr/40/97.106..97.108.md), and subparts [BB](/cfr/40/subpartBB.md) and [CC](/cfr/40/subpartCC.md) and subparts [FF](/cfr/40/subpartFF.md) through [HH](/cfr/40/subpartHH.md) of this part, a CAIR NOX opt-in unit shall be treated as a CAIR NOX unit for purposes of applying such sections and subparts of this part.
- (b) Solely for purposes of applying, as provided in this subpart, the requirements of subpart HH of this part to a unit for which a CAIR opt-in permit application is submitted and not withdrawn and a CAIR opt-in permit is not yet issued or denied under this subpart, such unit shall be treated as a CAIR NOX unit before issuance of a CAIR opt-in permit for such unit.

## Notes

### Authority

Authority: 42 U.S.C. 7401, 7403, 7410, 7426, 7491, 7601, and 7651, et seq.

### Source

Source: 65 FR 2727, Jan. 18, 2000, unless otherwise noted. 71 FR 25396, 25422, and 25443, Apr. 28, 2006