[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: 30CFR27.33] [Page 146] TITLE 30--MINERAL RESOURCES CHAPTER I--MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR PART 27--METHANE-MONITORING SYSTEMS--Table of Contents Subpart C--Test Requirements Sec. 27.33 Test to determine explosion-proof construction. Any assembly, subassembly, or component which, in the opinion of MSHA, requires explosion-proof construction shall be tested in accordance with the procedures stated in Part 18 of this subchapter.