75.1506—Refuge alternatives.
(1)
Prefabricated self-contained units, including the structural, breathable air, air monitoring, and harmful gas removal components of the unit, shall be approved under 30 CFR part 7; and
(2)
The structural components of units consisting of 15 psi stoppings constructed prior to an event shall be approved by the District Manager, and the breathable air, air monitoring, and harmful gas removal components of these units shall be approved under 30 CFR part 7.
(3)
Prefabricated refuge alternative structures that states have approved and those that MSHA has accepted in approved Emergency Response Plans (ERPs) that are in service prior to March 2, 2009 are permitted until December 31, 2018, or until replaced, whichever comes first. Breathable air, air-monitoring, and harmful gas removal components of either a prefabricated self-contained unit or a unit consisting of 15 psi stoppings constructed prior to an event in a secure space and an isolated atmosphere that states have approved and those that MSHA has accepted in approved ERPs that are in use prior to March 2, 2009 are permitted until December 31, 2013, or until replaced, whichever comes first. Refuge alternatives consisting of materials pre-positioned for miners to deploy in a secure space with an isolated atmosphere that MSHA has accepted in approved ERPs that are in use prior to March 2, 2009 are permitted until December 31, 2010, or until replaced, whichever comes first.
(b)
Except as permitted under paragraph (a)(3) of this section, each operator shall provide refuge alternatives with sufficient capacity to accommodate all persons working underground.
(1)
Refuge alternatives shall provide at least 15 square feet of floor space per person and 30 to 60 cubic feet of volume per person according to the following chart. The airlock can be included in the space and volume if waste is disposed outside the refuge alternative.
| Mining height (inches) | Unrestricted volume(cubic feet) per person* |
|---|---|
| 36 or less | 30 |
| >36-≤42 | 37.5 |
| >42-≤48 | 45 |
| >48-≤54 | 52.5 |
| >54 | 60 |
| * Includes an adjustment of 12 inches for clearances. | |
(2)
Refuge alternatives for working sections shall accommodate the maximum number of persons that can be expected on or near the section at any time.
(3)
Each refuge alternative for outby areas shall accommodate persons reasonably expected to use it.
(1)
Within 1,000 feet from the nearest working face and from locations where mechanized mining equipment is being installed or removed except that for underground anthracite coal mines that have no electrical face equipment, refuge alternatives shall be provided if the nearest working face is greater than 2,000 feet from the surface.
(2)
Spaced within one-hour travel distances in outby areas where persons work such that persons in outby areas are never more than a 30-minute travel distance from a refuge alternative or safe exit. However, the operator may request and the District Manager may approve a different location in the ERP. The operator's request shall be based on an assessment of the risk to persons in outby areas, considering the following factors: proximity to seals; proximity to potential fire or ignition sources; conditions in the outby areas; location of stored SCSRs; and proximity to the most direct, safe, and practical route to an intake escapeway.
(d)
Roof and rib support for refuge alternative locations shall be specified in the mine's roof control plan.
(e)
The operator shall protect the refuge alternative and contents from damage during transportation, installation, and storage.
(f)
A refuge alternative shall be removed from service if examination reveals damage that interferes with the functioning of the refuge alternative or any component.
(1)
If a refuge alternative is removed from service, the operator shall withdraw all persons from the area serviced by the refuge alternative, except those persons referred to in § 104(c) of the Mine Act.
(2)
Refuge alternative components removed from service shall be replaced or be repaired for return to service in accordance with the manufacturer's specifications.
(g)
At all times, the site and area around the refuge alternative shall be kept clear of machinery, materials, and obstructions that could interfere with the deployment or use of the refuge alternative.
(1)
A sign or marker made of a reflective material with the word “REFUGE” shall be posted conspicuously at each refuge alternative.
(2)
Directional signs made of a reflective material shall be posted leading to each refuge alternative location.
(i)
During use of the refuge alternative, the atmosphere within the refuge alternative shall be monitored. Changes or adjustments shall be made to reduce the concentration of methane to less than 1 percent; to reduce the concentration of carbon dioxide to 1 percent or less and excursions not exceeding 2.5 percent; and to reduce the concentration of carbon monoxide to 25 ppm or less. Oxygen shall be maintained at 18.5 to 23 percent.
(1)
Meets the requirements for portable fire extinguishers used in underground coal mines under this part;
(2)
Is appropriate for extinguishing fires involving the chemicals used for harmful gas removal; and
(3)
Uses a low-toxicity extinguishing agent that does not produce a hazardous by-product when activated.