Citing concerns that the underground mining industry might soon face a shortfall of NIOSH-approved one-hour escape respirators, NIOSH announced that it would allow the continued manufacture and sale of devices that meet older specifications. The announcement was published in the Dec. 28, 2016, issue of the , and was accompanied by a short guidance document available from the website of the NIOSH National Personal Protective Technology Laboratory as a .

According to the guidance document, representatives from MSHA and the underground mining industry have expressed doubts that enough “Cap 3” closed circuit escape respirators (CCERs) would be available for mines to meet MSHA regulations and ensure the uninterrupted respiratory protection of miners. A Cap 3 CCER is capable of delivering at least 80 liters of oxygen as specified in Subpart O of 42 C.F.R. Part 84. Cap 3 CCERs are roughly equivalent to one-hour breathing devices known in the mining industry as self-contained self-rescuers (SCSRs), whose specifications are described in 42 C.F.R. Part 84 Subpart H. Both CCERs and SCSRs are used to escape atmospheres that are immediately dangerous to life and health.

In response to concerns about the performance of SCSRs, NIOSH had published a final rule in March 2012 authorizing manufacturers to continue to make, label, and sell Subpart H-approved SCSRs only until April 9, 2015. Subsequent rules extended this deadline until Jan. 4, 2017.

The new rule published Dec. 28, 2016, in effect grants an additional one-year extension, stating that NIOSH “does not intend to revoke” approval of Subpart H, one-hour SCSRs that are manufactured, labeled, or sold prior to Jan. 4, 2018.

Further explanation of NIOSH’s rules regarding SCSRs and CCERs is available in the .