The National Institute for Occupational Safety and Health (NIOSH) invites comment on Laboratory and Field Performance of a Respirable Personal Dust Monitor NIOSH Docket #084

The information contained in this document is still in draft form and as such should not be considered as a final statement of NIOSH policy.

The National Institute for Occupational Safety and Health (NIOSH), through an informal partnership with industry, labor, and the Mine Safety and Health Administration, has developed and tested a new type of instrument known as the personal dust monitor (PDM). The dust monitor is an integral part of the cap lamp that miners normally carry to work and provides continuous information about the amount of respirable coal mine dust in the breathing zone of that individual. Testing was conducted in the laboratory to verify the instrument’s accuracy as received from the manufacturer and after a period of underground use of the instrument. In-mine testing determined the precision, durability, and miner acceptance. The laboratory testing verified previous work that there is a 95% confidence that the individual PDM measurements were within ±25% of the reference measurements. The means of the pre- and postmine accuracy verification test values for 25 PDMs were statistically equivalent. Data from the mines showed a field precision of 0.078 relative standard deviation for the PDM and 0.052 for the coal mine dust personal sampler unit. The PDM had about 90% availability for collecting valid information in over 8,000 hr of underground use. Anecdotal comments by miners indicated that they found the PDM more convenient to wear for sampling than currently used instruments. Additional data were collected to measure the equivalency of the PDM to the U.K. Mining Research Establishment standard as required by U.S. law. However, analysis of the data was more complex than originally anticipated because the increasing variance with concentration required use of a more sophisticated statistical model. Explanation of and results from this work will be the subject of a future publication. Under the broad range of test conditions covered in this work, the PDM functioned as well as the current sampler in terms of availability for use, accuracy, precision, and miner acceptance.

Laboratory and Field Performance of a Respirable Personal Dust Monitor	PDMReportOfInvestigationForReview.pdf (1,270KB; 54 pgs)
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The comment submission period for NIOSH Docket #84 closed at 5:00 p.m. EDT on October 31 , 2006