Section 149.641 - What are the structural fire protection requirements for accommodation spaces and modules?(a) Accommodation spaces and modules must be designed, located, and constructed so as to minimize the effects of flame, excess heat, or blast effects caused by fires and explosions; and to provide safe refuge from fires and explosions for personnel for the minimum time needed to evacuate the space.(b) The requirement in paragraph (a) of this section may be met by complying with 46 CFR 108.131 through 108.147 , provided that: (1) The exterior boundaries of superstructures and deckhouses enclosing these spaces and modules, including any overhanging deck that supports these spaces and modules, are constructed to the A-60 standard defined in 46 CFR 108.131(b)(2) for any portion that faces and is within 100 feet of the hydrocarbon source; and(2) The ventilation system has both a means of shutting down the system and an alarm at a manned location that sounds when any hazardous or toxic substance enters the system.(c) As an alternative to paragraph (b) of this section, the requirement in paragraph (a) of this section may be met by complying with a national consensus standard, as that term is defined in 29 CFR 1910.2 , for the structural fire protection of accommodation spaces and modules, and that complies with the standards set by a nationally recognized testing laboratory, as that term is defined by 29 CFR 1910.7 , for such protection, provided that: (1) All such spaces and modules on deepwater manned ports are provided with automatic fire detection and alarm systems. The alarm system must signal a normally manned area both visually and audibly, and be divided into zones to limit the area covered by a particular alarm signal;(2) Sleeping quarters are fitted with smoke detectors that have local alarms that may or may not be connected with the central alarm panel; and(3) Independent fire walls are constructed and installed so as to be of size and orientation sufficient to protect the exterior surfaces of the spaces or modules from extreme radiant heat flux levels, and provide the A-60 standard defined in 46 CFR 108.131(b)(2) .USCG-1998-3884, 71 FR 57651 , Sept. 29, 2006, as amended by USCG-2013-0397, 78 FR 39180 , July 1, 2013