30 CFR § 57.5071 Exposure monitoring.
(a) Mine operators must monitor as often as necessary to
effectively determine, under conditions that can be reasonably
anticipated in the mine, whether the average personal full-shift
airborne exposure to DPM exceeds the DPM limit specified in §
(b) The mine operator must provide affected miners and their
representatives with an opportunity to observe exposure monitoring
required by this section. Mine operators must give prior notice to
affected miners and their representatives of the date and time of
(c) If any monitoring performed under this section indicates that a
miner's exposure to diesel particulate matter exceeds the DPM limit
specified in § 57.5060, the operator must promptly post notice of
the corrective action being taken on the mine bulletin board, initiate
corrective action by the next work shift, and promptly complete such
(d)(1) The results of monitoring for diesel particulate matter,
including any results received by a mine operator from sampling
performed by the Secretary, must be posted on the mine bulletin board
within 15 days of receipt and must remain posted for 30 days. The
operator must provide a copy of the results to the authorized
representative of miners.
(2) The mine operator must retain for five years (from the date of
sampling), the results of any samples the operator collected as a
result of monitoring under this section, and information about the
sampling method used for obtaining the samples.