Section 7.503 - Application requirements(a) An application for approval of a refuge alternative or component shall include: (1) The refuge alternative's or component's make and model number, if applicable.(2) A list of the refuge alternative's or component's parts that includes-(i) The MSHA approval number for electric-powered equipment;(ii) Each component's or part's in-mine shelf life, service life, and recommended replacement schedule;(iii) Materials that have a potential to ignite used in each component or part with their MSHA approval number; and(iv) A statement that the component or part is compatible with other components and, upon replacement, is equivalent to the original component or part.(3) The capacity and duration (the number of persons it is designed to maintain and for how long) of the refuge alternative or component on a per-person per-hour basis.(4) The length, width, and height of the space required for storage of each component.(b) The application for approval of the refuge alternative shall include the following: (1) A description of the breathable air component, including drawings, air-supply sources, piping, regulators, and controls.(2) The maximum volume, excluding the airlock; the dimensions of floor space and volume provided for each person using the refuge alternative; and the floor space and volume of the airlock.(3) The maximum positive pressures in the interior space and the airlock and a description of the means used to limit or control the positive pressure.(4) The maximum allowable apparent temperature of the interior space and the airlock and the means to control the apparent temperature.(5) The maximum mine air temperature under which the refuge alternative is designed to operate when the unit is fully occupied.(6) Drawings that show the features of each component and contain sufficient information to document compliance with the technical requirements.(7) A manual that contains sufficient detail for each refuge alternative or component addressing in-mine transportation, operation, and maintenance of the unit.(8) A summary of the procedures for deploying refuge alternatives.(9) A summary of the procedures for using the refuge alternative.(10) The results of inspections, evaluations, calculations, and tests conducted under this subpart.(c) The application for approval of the air-monitoring component shall specify the following:(1) The operating range, type of sensor, gas or gases measured, and environmental limitations, including the cross-sensitivity to other gases, of each detector or device in the air-monitoring component.(2) The procedure for operation of the individual devices so that they function as necessary to test gas concentrations over a 96-hour period.(3) The procedures for monitoring and maintaining breathable air in the airlock, before and after purging.(4) The instructions for determining the quality of the atmosphere in the airlock and refuge alternative interior and a means to maintain breathable air in the airlock.(d) The application for approval of the harmful gas removal component shall specify the following: (1) The volume of breathable air available for removing harmful gas both at start-up and while persons enter through the airlock.(2) The maximum volume of each gas that the component is designed to remove on a per-person per-hour basis.