Section 75.1600-3 - Communications facilities; refuge alternatives(a) Refuge alternatives shall be provided with a communications system that consists of- (1) A two-way communication facility that is a part of the mine communication system, which can be used from inside the refuge alternative; and(2) An additional communication system and other requirements as defined in the communications portion of the operator's approved Emergency Response Plan. 73 FR 80700 , Dec. 31, 2008