[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: 30CFR18.14] [Page 93-94] TITLE 30--MINERAL RESOURCES CHAPTER I--MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR PART 18--ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES--Table of Contents Subpart A--General Provisions Sec. 18.14 Identification of tested noncertified explosion-proof enclosures. An enclosure that meets all applicable requirements of this part, but has not been certified by MSHA, shall be identified by a permanent marking on it in a conspicuous location. The design of such marking shall consist of capital letters USMSHA not less than \1/4\ inch [[Page 94]] in height, enclosed in a circle not less than 1 inch in diameter. [33 FR 4660, Mar. 19, 1968, as amended at 43 FR 12314, Mar. 24, 1978] st