---
kind: "section"
citation: "40 C.F.R. § 63.179"
title: "40"
number: "63.179"
heading: "Alternative means of emission limitation: Enclosed-vented process units."
url: "https://uscodex.org/cfr/40/63.179"
---

# §63.179. Alternative means of emission limitation: Enclosed-vented process units.


Process units enclosed in such a manner that all emissions from equipment leaks are vented through a closed-vent system to a control device meeting the requirements of [§ 63.172](/cfr/40/63.172.md) of this subpart are exempt from the requirements of [§ 63.163, through 63.171](/cfr/40/63.163..63.171.md), and §§ [63.173](/cfr/40/63.173.md) and [63.174](/cfr/40/63.174.md) of this subpart. The enclosure shall be maintained under a negative pressure at all times while the process unit is in operation to ensure that all emissions are routed to a control device.


## Notes

### Source

Source: 59 FR 19568, Apr. 22, 1994, unless otherwise noted.

### Authority

Authority: 42 U.S.C. 7401 et seq.

### Source

Source: 57 FR 61992, Dec. 29, 1992, unless otherwise noted.