(a) The respirable dust sampling required by this part shall be done
by a certified person.
(b) To be certified, a person shall pass the MSHA examination on
sampling of respirable coal mine dust.
(c) A person may be temporarily certified by MSHA to take respirable
dust samples if the person receives instruction from an authorized
representative of the Secretary in the methods of collecting and submitting
samples under this rule. The temporary certification shall be withdrawn if
the person does not successfully complete the examination conducted by MSHA
on sampling of respirable coal mine dust within six months from the issue
date of the temporary certification.