In a statement provided to ILN late Tuesday, CSE president Scott Shearer acknowledged the findings of NIOSH, and the investigation it and MSHA have taken on together regarding the field-deployed SCSRs. However, he said, he had not to that point been given a final directive from either agency on the SR-100.

“CSE voluntarily ceased production of the SR-100 when the company’s internal quality control process identified a possible issue with the oxygen cylinder,” he said.

“We have remained committed and have been working with the agencies for some time to resolve any and all concerns. Once we receive final notification from the regulatory agencies, we will continue to develop appropriate next steps.”

As of press time, the SR-100s were still in active use across the nation’s coal operations, as neither federal agency ordered a withdrawal.

An ILN request for comment from MSHA assistant secretary Joseph Main about the report, and whether the agency was planning a directive to pull the units from service, was not returned Wednesday.

In the meantime, Shearer said the company remains committed to the industry.

“We want all of our customers to know that we are prepared to support their needs for SCSRs,” he said.

“As we gain more information we will keep our customers informed."

NIOSH’s long-awaited report, released Monday, detailed the development of a protocol for testing 500 of the more than 70,000 deployed SCSRs across US mines to determine whether there was a prevalence of a lack of sufficient start-up oxygen in the widely-used SR-100s.

Researchers assessed the group to determine if the units could be accepted as meeting the limiting quality (LQ) 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,” it said.

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

In its findings, NIOSH noted that the units it observed that exhibited excessive start-up oxygen loss had been carried by a worker for at least some portion of their deployed lives, and exhibited typical conditions of conforming fielded units.

It reported that the unit with the largest total start-up oxygen loss was also the oldest of the group, but is also confirmed that the next largest total loss measured was in one of the two newest units.

Pennsylvania-based CSE said in a May 2010 user notice that it recommended redundancy in the event of an oxygen starter failure.

“If for any reason a unit does not inflate the breathing bag, the user should don another unit if one is readily available,” the company instructed.

“If a second unit is not readily available, the manual start should be used.”

In 2011, the company unveiled its self-rescuer long duration (SRLD), touted to be the smallest, lightest, and fastest working unit available in its class.

“The development process for the new SRLD has been extensive and has spanned more than a decade and numerous prototypes, thousands of man hours and investment to develop this vital rescuer device,” Shearer said last July.

The product’s technology is contained in a lightweight package, and includes an oxygen starter unit designed and manufactured by compressed gas cylinder supplier Leland.

The SRLD offers a 40% faster production of oxygen at the start up, as well as a 10% total increase in oxygen production.

It also includes an irreversible seal indicator, noting breach of water vapor or moisture, as well as a temperature indicator, to guide miners and users upon inspection as to what units should be removed from service.

“CSE has pulled out all of the stops to develop what we know will be the best operating unit with the highest quality performance for the mining industry,” Shearer said at the time.

“This product is designed with both miner safety and miner convenience in mind.”