The unit is MineARC’s safe scrubbing and air conditioning system that maintains the refuge chamber’s internal environment by continually removing the buildup of carbon dioxide, carbon monoxide and heat generated by the miners, as they await rescue, said company officials.

MSHA’s approval letter to MineARC stated that “The design of this harmful gas removal component meets the applicable requirements of Title 30 Code of Federal Regulations, Section 7.508 (30CFR Section 7.508).”

MineARC Systems America general manager James Rau called it a “significant” step for the company. “Customers can purchase from us with the confidence that our refuges meet the highest global safety standards in coal mining, relating to refuge alternatives,” he said.

Moreover, the MARC unit is “the first cooling system approved for coal mine refuge alternatives,” he added. “Testing has shown that the refuge can operate in high temperatures while still maintaining the 95°F internal apparent temperature threshold.”

MSHA’s 30CFR Section 7.508, commonly known as MSHA’s “Final Rule,” was first introduced into U.S. mining legislation in 2008 following calls for more stringent requirements for refuge chamber manufacturers and coal mines.

To comply with new approvals, MineARC implemented a state-of-the-art production process including a purpose built oxygen clean room, comprehensive component tracking and detailed standard operating procedures, said company officials. Existing customer units are currently being returned to MineARC and upgraded to comply with new approvals.