---
kind: "section"
citation: "46 C.F.R. § 108.173"
title: "46"
number: "108.173"
heading: "Class I, Division 2 locations."
url: "https://uscodex.org/cfr/46/108.173"
---

# §108.173. Class I, Division 2 locations.


The following are Class I, Division 2 locations:

- (a) An enclosed space that has any open portion of the mud circulating system from the final degassing discharge to the mud suction connection at the mud pit.
- (b) **A location in the weather that is—**
  - (1) Within the boundaries of the drilling derrick up to a height of 3 m (10 ft.) above the drill floor;
  - (2) Below the drill floor and within a radius of 3 m (10 ft.) of a possible source of gas release; or
  - (3) Within 1.5 m (5 ft.) of the boundaries of any ventilation outlet, access, or other opening to a Class I, Division 2 space.
- (c) **A location that is—**
  - (1) Within 1.5 m (5 ft.) of a semi-enclosed Class I, Division 1 location indicated in [§ 108.171(b)](/cfr/46/108.171.md?p=b); or
  - (2) Within 1.5 m (5 ft.) of a Class I, Division 1 space indicated in [§ 108.171(e)](/cfr/46/108.171.md?p=e).
- (d) A semi-enclosed area that is below and contiguous with the drill floor to the boundaries of the derrick or to the extent of any enclosure which is liable to trap gasses.
- (e) A semi-enclosed derrick to the extent of its enclosure above the drill floor or to a height of 3 m (10 ft.) above the drill floor, whichever is greater.
- (f) Except as provided in [§ 108.175](/cfr/46/108.175.md) an enclosed space that has an opening into a Class I, Division 2 location.

## Notes

### Authority

Authority: 43 U.S.C. 1333; 46 U.S.C. 3102, 3306; DHS Delegation No. 00170.1, Revision No. 01.4.

### Source

Source: CGD 73-251, 43 FR 56808, Dec. 4, 1978, unless otherwise noted.