SCSRs received new public attention five years ago, after Sago Mine Disaster survivor Randal McCloy testified that the SCSRs of four of the 12 miners trapped by the Jan. 2, 2006, explosion wouldn't start.
Over the years, coal miners had expressed similar complaints about SCSRs not starting or appearing to start slowly. Government and industry officials have generally dismissed those complaints. They said the problem was that miners weren't properly trained or didn't understand how their SCSRs worked.
Then last year, MSHA and NIOSH launched a joint investigation of problems that were eventually traced to the oxygen cylinders used in the initial start-up of the SR-100 devices. Initially, CSE said it had instituted a "recall" of the troubled units, but later conceded it had not actually ordered coal companies to stop using the devices.
In lawsuits after the Sago disaster, families of the miners were investigating concerns that the SR-100 cylinders -- made by a South African company -- somehow leaked, leaving the units without enough oxygen to start properly. Those suits were settled, and the terms were kept confidential.
Kravitz said the new CSE device uses different oxygen cylinder and starter components that don't involve the threaded connections that could have been the problem with the SR-100. "We definitely think that is going to fix the problem," he said.
Roland BerryAnn, deputy director of the NIOSH lab that reviewed the new device, said his staff did not do a direct comparison with the SR-100 because CSE submitted an application for a new product, rather than changes to its existing devices.
"If the new unit had been as an action to correct the identified problem, we would have done a comparative to see how the problem was corrected," BerryAnn said earlier this week.
BerryAnn also said NIOSH does not test breathing devices to see how long they will last, but only to ensure that they will meet the 60-minute requirement in federal law.
In a notice dated July 29, but not made public until Wednesday, NIOSH said it had determined a potential failure rate of the SR-100's oxygen starter cylinders of between 1.25 percent and 2 percent -- meaning as many as 1,400 faulty units could be in use.
MSHA doesn't know how long it will take to phase out the SR-100s. "We think we're going to have to work that out with NIOSH," Kravitz said.
Reach Ken Ward Jr. at kw...@wvgazette.com or 304-348-1702.