[Code of Federal Regulations] [Title 46, Volume 4] [Revised as of October 1, 2006] From the U.S. Government Printing Office via GPO Access [CITE: 46CFR108.170] [Page 126] TITLE 46_SHIPPING (This book contains parts 90 to 139) CHAPTER I--COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PART 108_DESIGN AND EQUIPMENT--Table of Contents Subpart B_Construction and Arrangement Sec. 108.170 Definitions. (a) Classified locations are those in which flammable hydrocarbon gas or vapors, resulting from the drilling operations, may be present in quantities sufficient to produce an explosive or ignitable mixture. Location of these areas affect the design of the units' machinery, electrical, and ventilation systems. (See Notes 1 and 2). (b) For the purpose of this subpart ``semi-enclosed location'' means a location where natural conditions of ventilation are notably different from those on open decks due to the presence of structures such as roofs, windbreaks, or bulkheads. Notes: 1. Further requirements with respect to hazardous locations are contained in part 111, subpart 111.105, of this chapter. 2. For specific requirements for machinery and electrical installations on mobile offshore drilling units see Subchapters ``F'' and ``J'' of this chapter. [CGD 73-251, 43 FR 56808, Dec. 4, 1978, as amended by CGD 94-108, 61 FR 28270, June 4, 1996]