Program Policy Manual - VOLUME V - Mine Safety and Health ...

MSHA PROGRAM POLICY MANAUL VOLUME V
Subpart B Dust Standards, Rights of Part 90 Miners
90.100 Respirable Dust Standard
The mine operator has a 20-calendar-day grace period in which
to assure that a Part 90 miner is in an environment of 1.0
milligrams per cubic meter of air. If any sampling conducted
after the twentieth calendar day by either MSHA or the operator
shows this standard has been exceeded, the inspector shall
issue a 104(a) citation for a violation of 90.100.
This section in the amended Part 90 rule supersedes the
203(b)(2) dust standard which allowed mine operators to place
miners in an environment with concentrations of respirable dust
that were the lowest attainable below 2.0 mg/m 3 when the 1.0
mg/m 3 standard was not attainable. In other words, Part 90
miners can only work where concentrations of dust are at or
below 1.0 mg/m 3 .
90.101 Dust Standard When Quartz is Present
The 1.0 mg/m 3 standard is applicable only when the amount of
quartz is equal to or less than 10 percent in the Part 90
miner's environment in the active workings. Because the Part
90 miner's environment could be at any location (MMU, DWP or
DA), Section 90.101 shall be cited only if the amount of quartz
in the Part 90 miner's samples exceeded 10 percent and if this
miner was exposed to concentrations of respirable dust that
exceeded the reduced dust standard.
The maximum standard for a Part 90 miner is l.0 mg/m 3 of air.
Therefore, quartz must be 11.0 percent or greater to cause a
reduction in the dust standard. Conversely, when a Part 90
miner is on a reduced standard and a subsequent analysis is
10.9 percent of quartz or less, do not raise the dust standard
above 1.0 mg/m 3 of air.
90.102(a) Transfer, Shift Protection
At some coal mines, mine employees are rotated periodically to
different shifts. Under the rule the mine operator must allow
the Part 90 miner to continue to work on his or her shift
rotation. Exception:
The operator may transfer a Part 90 miner without regard to
these job and shift limitations if the respirable dust
concentration in the position of the Part 90 miner complies
with the dust standard, but circumstances require changes in
job assignments at the mine. Reductions in workforce or
February 2003 (Release V-33) 218