CFR > Title 30 - Mineral Resources > CHAPTER I—MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR > SUBCHAPTER B—TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS (parts 5 to 36) > PART 33—DUST COLLECTORS FOR USE IN CONNECTION WITH ROCK DRILLING IN COAL MINES > SUBPART A—General Provisions (§33.1 to §33.13) > 33.4—Types of dust collectors for which certificates of approval may be granted.

33.4—Types of dust collectors for which certificates of approval may be granted.

(a) Certificates of approval will be granted only for completely assembled dust-collector or combination units; parts or subassemblies will not be approved.
(b) The following types of equipment may be approved: Dust-collector or combination units having components designed specifically to prevent dissemination of airborne dust generated by drilling into coal-mine rock strata in concentrations in excess of those hereinafter stated in § 33.33 as allowable, and to confine or control the collected dust in such manner that it may be removed or disposed of without dissemination into the mine atmosphere in quantities that would create unhygienic conditions.