About
NIOSH conducted research to evaluate the effectiveness of purging of mine refuge alternatives (RAs). Two questions were addressed experimentally: 1) Does the current generation of mobile refuge alternatives meet the requirements of 30CFR§7.508(c)(2) which requires RAs to be capable of purging the internal atmosphere from 400 ppm of carbon monoxide (CO) to 25 ppm? 2) What is the relationship between the concentration of noxious gases in the mine atmosphere external to the refuge alternative and the concentration that will be present inside the refuge alternative following entry of miners but prior to purging? The goal of the second question was to evaluate the appropriateness of the 400-ppm criterion, given that ambient post-accident mine concentrations of CO can be in the thousands of ppm.
Additional information
Suggested citation
NIOSH [2014]. Investigation of Purging and Airlock Contamination of Mobile Refuge Alternatives. By Bauer ER, Matty TJ, Thimons ED. Pittsburgh, PA: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, DHHS (NIOSH) Publication 2014–116, RI 9694.
Revisions
This publication was revised on March 20, 2014, to correct an editorial omission in the recommendations on page 42.