NIOSH Respirator User Notice
December 22, 1999

The Mine Safety and Health Administration reported to NIOSH on December 8, 1999, that a miner who either donned, or attempted to don, an SR-100 SCSR during a brief electrical fire in a mine, suffered smoke inhalation requiring medical treatment at a hospital.  A deteriorated breathing tube on the SR-100 SCSR that was opened by the miner prevented the unit from providing adequate protection from the smokey atmosphere.  The SR-100 SCSR opened by the miner during the mine fire was manufactured in 1991.

In an effort to determine if this was an isolated incident, MSHA opened additional SR-100 SCSRs at the mine where the fire occurred and identified three (3) more SR-100 SCSRs containing breathing tubes in an unusable condition.  Subsequently, three hundred twenty eight (328) SR-100 SCSRs originally issued to MSHA inspectors were opened by MSHA and NIOSH at NIOSH's Pittsburgh Research Laboratory on December 10, 1999.  Of these three hundred twenty eight (328), six (6) more were found to have breathing tubes in an unusable condition.  To date, ten (10) SR-100 SCSRs manufactured from 1990 through January 1993 have been found to have unusable breathing tubes.  The breathing tube material was changed in June 1994 from natural rubber to silicone.  None of the units manufactured after that date, containing the newer breathing tube material, were found to be in an unusable condition but there has been no finding at this time that the use of natural rubber caused the problem.

The cause of the problem observed on the older breathing tube material has not yet been conclusively determined.  The manufacturer's preliminary determination is that exposure to temperatures above the recommended limit of 130o F. has caused deterioration of the breathing tubes.  The breathing tube is enclosed within the sealed case of the unit, which may not be opened prior to actual use, and there have been no observable differences in the external condition of units found with an unusable breathing tube. Therefore, CSE SR-100 SCSRs manufactured before June 7, 1994, may contain this critical safety defect and all are subject to corrective action to assure that they have not been similarly affected.

Users of CSE SR-100 SCSR devices manufactured prior to June 7, 1994, should, in accordance with availability, do one of the following as expeditiously as possible:

  1. Have the devices retrofitted by the manufacturer;
  2. Replace each device with a CSE unit manufactured after June 7, 1994; or
  3. Obtain other approved SCSRs.

The following manufacturers, listed in alphabetical order, produce MSHA/NIOSH approved SCSR devices:

CSE Corporation, telephone number, (412) 856-9200 or (800) 245-2224
Attention, Scott Shearer

Draeger, telephone number, (800) 858-1739 or 1741
Attention, Mary Doane, or

Mine Safety Appliances Company (MSA), telephone number, (412) 967-3151
Attention, John Hierbaum

Ocenco Incorporated, telephone number, (262) 947-9000
Attention, Richard Vanderveer

If it is not possible to replace or have repaired all CSE SR-100 SCSRs manufactured prior to June 7, 1994, immediately, users should consider making additional SCSR devices available in the work area to provide workers with access to more than one device for use in the event of an emergency.

If you have any questions, please contact MSHA at (412) 386-6923 or NIOSH at 1-800-35NIOSH