---
kind: "section"
citation: "30 C.F.R. § 33.31"
title: "30"
number: "33.31"
heading: "Test space."
url: "https://uscodex.org/cfr/30/33.31"
---

# §33.31. Test space.

- (a) Drilling tests shall be conducted in a test space formed by two curtains suspended across a mine opening in such a manner that the volume of the test space shall be approximately 2,000 cubic feet.
- (b) No mechanical ventilation shall be provided in the test space during a drilling test, except such air movement as may be induced by operation of drilling- or dust-collecting equipment.
- (c) All parts of a unit or system shall be within the test space during a drilling test.

## Notes

### Authority

Authority: 30 U.S.C. 957, 961.

### Source

Source: Schedule 25B, 25 FR 6473, July 9, 1960, unless otherwise noted.