[Code of Federal Regulations] [Title 30, Volume 1] [Revised as of July 1, 2002] From the U.S. Government Printing Office via GPO Access [CITE: 30CFR33.4] [Page 153] TITLE 30--MINERAL RESOURCES CHAPTER I--MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR PART 33--DUST COLLECTORS FOR USE IN CONNECTION WITH ROCK DRILLING IN COAL MINES--Table of Contents Subpart A--General Provisions Sec. 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 Sec. 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.