30 CFR § 57.22228 Preshift examination (I-A, I-C, II-A, III, and V-A mines). (a) Preshift examinations shall be conducted within three hours prior
to the start of the shift for which the examination is being made. (b) Prior to the beginning of a shift following an idle shift, a
competent person shall test the mine atmosphere for methane at all work
places before persons other than examiners enter the mine. (c) When one shift immediately follows another, a competent person
shall test the mine atmosphere at each active working face for methane before
work is started on that shift. (d) A competent person shall test the mine atmosphere at each face
blasted before work is started. (e) Except in Subcategory I-C or Category III mines, vehicles used
for transportation when examining the mine shall be approved by MSHA under
the applicable requirements of 30 CFR parts 18 through
36.
[52 FR, 24941, July 1, 1987, as amended at 53 FR 9615, Mar. 24, 1988]
