30 CFR § 33.31 - Test space.

---
identifier: "/us/cfr/t30/s33.31"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "30 CFR § 33.31 - Test space."
title_number: 30
title_name: "Mineral Resources"
section_number: "33.31"
section_name: "Test space."
chapter_name: "MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR"
subchapter_number: "B"
subchapter_name: "TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS"
part_number: "33"
part_name: "DUST COLLECTORS FOR USE IN CONNECTION WITH ROCK DRILLING IN COAL MINES"
positive_law: false
currency: "2026-03-24"
last_updated: "2026-03-24"
format_version: "1.1.0"
generator: "[email protected]"
authority: "30 U.S.C. 957, 961."
regulatory_source: "Schedule 25B, 25 FR 6473, July 9, 1960, unless otherwise noted."
cfr_part: "33"
---


# 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.