30 CFR § 7.504
Refuge alternatives and components; general requirements.
(a) Refuge alternatives and components:
(1) Electrical components that are exposed to the mine atmosphere
shall be approved as intrinsically safe for use. Electrical components
located inside the refuge alternative shall be either approved as
intrinsically safe or approved as permissible.
(2) Shall not produce continuous noise levels in excess of 85 dBA
in the structure's interior.
(3) Shall not liberate harmful or irritating gases or particulates
into the structure's interior or airlock.
(4) Shall be designed so that the refuge alternative can be safely
moved with the use of appropriate devices such as tow bars.
(5) Shall be designed to withstand forces from collision of the
refuge alternative structure during transport or handling.
(b) The apparent temperature in the structure shall be controlled
(1) When used in accordance with the manufacturer's instructions
and defined limitations, the apparent temperature in the fully occupied
refuge alternative shall not exceed 95 degrees Fahrenheit ([deg]F).
(2) Tests shall be conducted to determine the maximum apparent
temperature in the refuge alternative when used at maximum occupancy
and in conjunction with required components. Test results including
calculations shall be reported in the application.
(c) The refuge alternative shall include:
(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 accommodations for an
additional communication system and other requirements as defined in
the communications portion of the operator's approved Emergency
(2) Lighting sufficient for persons to perform tasks.
(3) A means to contain human waste effectively and minimize
(4) First aid supplies.
(5) Materials, parts, and tools for repair of components.
(6) A fire extinguisher that--
(i) Meets the requirements for portable fire extinguishers used in
underground coal mines under part 75;
(ii) Is appropriate for extinguishing fires involving the chemicals
used for harmful gas removal; and
(iii) Uses a low-toxicity extinguishing agent that does not produce
a hazardous by-product when deployed.
(d) Containers used for storage of refuge alternative components or
provisions shall be--
(1) Airtight, waterproof, and rodent-proof;
(2) Easy to open and close without the use of tools; and
(3) Conspicuously marked with an expiration date and instructions