Pennsylvania-based CSE voluntarily requested that approval for the SCSR be rescinded, which is consistent with an earlier MSHA notice that all units be removed from service by the end of this year.

The device was first approved as a one-hour SCSR on February 23, 1989, under approval number TC-13F-0239.

All units still in service at the nation’s mines should be removed from service by December 31 and replaced with another approved SCSR unit.

Any operators with questions regarding the enforcement status of SR-100s are asked to speak with MSHA or the Occupational Safety and Health Administration.

Research arm NIOSH was the overseer of a joint investigation in 2012 that determined the units did not conform to safety requirements and reported its findings to MSHA in April that year.

“Due to the large number of CSE SR-100s in underground coal mines, multiple SCSRs available to miners, the low probability of failure and the shortage of immediately available replacements, MSHA and NIOSH have determined that an orderly phase-out will better protect the safety of miners than immediate withdrawal of the devices,” MSHA assistant secretary of labor Joseph Main said at the time.

After pulling 500 units at random from across US coal mining operations, NIOSH assessed the group to determine if the units could be accepted as meeting the limiting quality rate of 1.25% for start-up oxygen performance – or no more than three failures from the entire lot.

“NIOSH observed five start-up oxygen failures in the 500 units it tested,” the agency said in its report.

“The maximum number of failures allowed under the limiting quality rate of 1.25% was exceeded, therefore, the 1% maximum allowable failure rate under the protocol was not met.”

MSHA and NIOSH jointly approve respirators for use in the nation’s mines.

Under the Mine Improvement and New Emergency Response Act of 2006, or MINER Act, all US mines were ordered to provide additional SCSRs for every miner working underground in working sections, on mantrips, in escapeways and outby workways and travelways.

The rule also required SCSRs to be readily accessible in case of an emergency.

Almost immediately after the announcement was made at that time, producer CSE responded that it had taken its responsibility to the industry very seriously.

“During this process, we have been upfront, transparent and maintained open lines of communication, not only with MSHA and NIOSH but with our customers as well,” the company said.

“We have dedicated all of our resources to solve any concerns during the course of the inquiry.

“We are fully prepared to meet our customers’ needs for SCSRs within the timeline set by the government.”

Additionally, CSE confirmed it had “complete confidence” in its entire line of rescuers and pledged to support the needs of its customers during the forthcoming transition time as well as in the future.

Many mines not using the CSE model SCSRs opt to use Ocenco units.

Ocenco’s two primary products are the M-20.2, a belt-worn unit designed for 20 minutes of breathable air and the EBA 6.5, often stored in caches, which allows for more than 90 minutes of oxygen.

A guide to the care and maintenance of Ocenco M-20 units is available at www.msha.gov/InteractiveTraining/SCSR/Ocenco%20M-20/lesson06/Instructors_Guide_OCM20.pdf.

Further information and answers to frequently asked questions on the CSE phase-out are available on MSHA’s single source CSE SR-100 site at www.msha.gov/Alerts/CSESR100/CSESR100Alerts.asp.