Self-Contained Self-Rescuer Long Term Field Evaluation: Combined Eighth and Ninth Phase Results

NIOSH and OSHA conduct a Long Term Field Evaluation (LTFE) program to evaluate deployed self-contained self-rescuers (SCSRs). The objective of the program is to evaluate how well SCSRs endure the underground coal mining environment with regard to both physical damage and aging when they are deployed in accordance with Federal regulations (30 CFR 75.1714). This report presents findings of the combined eighth and ninth phases of the LTFE. For these phases, over four hundred SCSRs were evaluated. The units tested include the CSE SR-100, Draeger Oxy K-Plus, MSA Life-saver 60, and the OCENCO EBA 6.5. The OCENCO M-20 was evaluated only in Phase 9. Testing was performed between December 2000 and April 2004. Results of the evaluation indicate that all SCSRs experience some performance degradation due to the mining environment. Observed degradation varies from elevated levels of carbon dioxide, high breathing resistance, and reduced capacity. Although the results of these tests are useful for observing performance of the tested SCSRs, they are not representative of all deployed SCSRs. A new evaluation protocol, with revised sampling strategies, test methods, and reporting procedures, is currently being designed to enhance the generalizability of the results. This program will be implemented following completion of Phase 10 of the current LTFE protocol.