[Code of Federal Regulations] [Title 30, Volume 1] [Revised as of July 1, 2006] From the U.S. Government Printing Office via GPO Access [CITE: 30CFR33.37] [Page 168-169] 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 C_Test Requirements Sec. 33.37 Test procedure. (a) Roof drilling: Drilling shall be done in friable strata, similar to the roof in the Bureau's Experimental Mine, which tends to produce large scale-like cuttings. (b) Horizontal drilling: Drilling shall be done in strata comparable in hardness to that of coal-mine draw slate. Holes shall be started near the roof of the test space under conditions simulating the drilling of draw slate in coal mining. (c) Down drilling: Drilling shall be done in typical mine floor strata with a pneumatic percussion-type drill. Five holes shall be drilled vertically and five holes shall be drilled at an angle. (d) At MSHA's discretion drilling in ``on site'' strata may be acceptable in [[Page 169]] lieu of strata requirements in paragraphs (a), (b), and (c) of this section. (See Sec. 33.20(a).)