30 CFR § 72.800 - Single, full-shift measurement of respirable coal mine dust.
The Secretary will use a single, full-shift measurement of respirable coal mine dust to determine the average concentration on a shift since that measurement accurately represents atmospheric conditions to which a miner is exposed during such shift. Noncompliance with the applicable respirable dust standard or the applicable respirable dust standard when quartz is present, in accordance with subchapter O of this chapter, is demonstrated when a single, full-shift measurement taken by MSHA meets or exceeds the applicable ECV in Table 70-1, 71-1, or 90-1 that corresponds to the applicable standard and the particular sampling device used. Upon issuance of a citation for a violation of the applicable standard, and for MSHA to terminate the citation, the operator shall take the specified actions in subchapter O of this chapter.