[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: 30CFR18.22] [Page 94-95] 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 B--Construction and Design Requirements Sec. 18.22 Boring-type machines equipped for auxiliary face ventilation. Each boring-type continuous-mining machine that is submitted for approval shall be constructed with an unobstructed continuous space(s) of not less than 200 square inches total cross-sectional area on or within the machine to [[Page 95]] which flexible tubing may be attached to facilitate auxiliary face ventilation.