Loss of start-up oxygen in CSE SR-100 self-contained self-rescuers.
Stein-R; Ahlers-H; Berry Ann-R
Pittsburgh, PA: U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, DHHS (NIOSH) Publication No. 2012-139, 2012-139; :1-16
This report describes a National Institute for Occupational Safety and Health (NIOSH) and Mine Safety and Health Administration (MSHA) investigation assessing the prevalence of a lack of sufficient start-up oxygen in CSE SR-100 self-contained self-rescuer (SCSR) devices. The availability of sufficient start-up oxygen is critical to the performance of the SR-100. As part of a routine field testing program of SCSRs used in coal mines, NIOSH and MSHA detected two SR-100s that lacked sufficient start-up oxygen. CSE Corporation subsequently discovered one SCSR that lacked sufficient start-up oxygen in that company's internal quality control program and voluntarily stopped further production and sales of SR-100s. NIOSH developed a protocol to test for the presence of start-up oxygen in field-deployed SR100s. The purpose of the test was to determine if the failure rate of the start-up oxygen in the population of 70,000 field-deployed units exceeded 1%. NIOSH and MSHA used American Society for Quality (ASQ), Sampling Procedures and Tables for Inspection of Isolated Lots by Attributes (ASQC Q3-1988). In assessing the SR-100s, if no more than 3 failures of start-up oxygen occurred in the 500-unit random sample, the SR-100 could be accepted as meeting the Limiting Quality (LQ) rate of 1.25% for start-up oxygen performance. NIOSH tested five hundred field-deployed devices collected from coal mines throughout the United States. NIOSH observed 5 start-up oxygen failures in the 500 units it tested. 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.
Mining-equipment; Mining-industry; Underground-mining; Self-contained-self-rescuers; Laboratory-testing; Protective-equipment; Personal-protective-equipment; Respiratory-protective-equipment; Respiratory-protection
NTIS Accession No.
(NIOSH) 2012-139; B04252012
Public Safety; Mining
National Institute for Occupational Safety and Health