30 CFR § 57.22601 Blasting from the surface (I-A mines).
(a) All development, production, and bench rounds shall be initiated
from the surface after all persons are out of the mine. Persons shall not
enter the mine until ventilating air has passed over the blast area and
through at least one atmospheric monitoring sensor.
(b) After blasting, if the monitoring system indicates that methane
in the mine is less than 1.0 percent, persons may enter the mine. All places
blasted shall be tested for methane by a competent person before work is
(c) If the monitoring system indicates the presence of 1.0 percent or
more methane, persons other than examiners shall not enter the mine until the
mine has been examined by a competent person and the methane content has been
reduced to less than 1.0 percent.
(d) 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]
EFFECTIVE DATE NOTE: At 53 FR 9615, Mar. 24, 1988, §57.22601 was stayed until