MSHA - Code of Federal Regulations - 30 CFR 70.210
30 CFR § 70.210
Respirable dust samples; report to operator; posting.
(a) The Secretary shall provide the operator with a report of the
following data on respirable dust samples as soon as practicable:
(1) The mine identification number;
(2) The mechanized mining unit or designated area within
the mine from which the samples were taken;
(3) The concentration of respirable dust, expressed in
milligrams per cubic meter of air, for each valid sample;
(4) The average concentration of respirable dust,
expressed in milligrams per cubic meter of air, for all valid samples;
(5) The occupation code, where applicable, and;
(6) The reason for voiding any samples.
(b) Upon receipt, the operator shall post this data for at least 31
days on the mine bulletin board.
For further information: See MSHA's Program Policy Manual