NIOSH Respirators User Notice
NOTE: This page is archived for historical purposes and is no longer being maintained or updated.
Issue Date: June 23, 2010
From: Heinz Ahlers, Chief, Technology Evaluation Branch, National Personal Protective Technology Laboratory
Subject: Updated Users Notice Concerning CSE SR-100 Self-Contained Self-Rescuer (SCSR)
The National Institute for Occupational Safety and Health (NIOSH) and the Mine Safety and Health Administration (MSHA) are currently investigating a self-reported failure of the oxygen starter in the SR-100 self-contained, self-rescuer (SCSR) manufactured by the CSE corporation. The SR-100 is approved by NIOSH and MSHA as a one-hour SCSR under TC-13F-0239. http://www.cdc.gov/niosh/npptl/resources/pressrel/letters/lttr-06232010.html
The problem reported by CSE was initially identified as related to two production lots, affecting roughly 1% of manufactured devices in these lots, but has since expanded in scope. It is currently thought that more production lots could be involved at the same 1% rate. CSE has stopped production of the SR-100 pending identification of the failure mode and resolution of the problem.
NIOSH and MSHA have also been investigating oxygen starter failures observed in field-deployed units in the Long Term Field Evaluation (LTFE) Program. The failure mode of the observed failures may, or may not be the same reported by CSE, but the investigation has suggested that rough handling, poor inspection techniques, and exposure to temperatures exceeding manufacturer specifications increase the probability of an oxygen starter failure. This information again underscores the importance of strict compliance with all of the manufacturer’s inspection procedures, including the acoustic solids movement detector test, and the careful observation of the temperature and humidity warning detectors. All mine operators and workers at mines using the CSE SR-100 need to be aware of and follow this guidance. A link to the inspection procedure appears at: http://www.msha.gov/interactivetraining.htm#scsr
The total number of SR-100 devices with oxygen starter problems is not currently known. As stated previously, CSE estimates it is no more than 1% in production lots when leaving the factory, but the failure rate can increase with unmonitored exposures to rough handling and temperatures exceeding manufacturer specifications.
Since CSE is not currently producing the SR-100, no SR-100 replacements are available for deployed units that fail to pass inspection or reach their expiration date. Operators should provide miners with additional supplemental training to ensure that miners know what to do should their SCSR fail to activate. All miners should have ready access to a spare SCSR in case the first one they try to activate fails. A link to the NIOSH Office of Mine Safety and Health Research notice on precautions and training on oxygen activation for SCSRs appears at: http://www.cdc.gov/niosh/mining/notices/default.htm