30 CFR § 57.22304 Approved equipment (II-A mines). (a) Cutting and drilling equipment used at a face or bench shall be
approved by MSHA under the applicable requirements of 30 CFR parts
18 through 36. (b) While cutting or drilling is in progress, equipment not approved
by MSHA under the applicable requirements of 30 CFR parts 18 through 36 shall remain at least 100 feet from the face or bench
being mined. (c) Tests for methane shall be conducted immediately before
nonapproved equipment is taken to a face or bench after blasting. (d) Mine power transformers and stationary equipment not approved by
MSHA under the applicable requirements of 30 CFR parts 18 through
36 shall be installed in fresh air or downwind from an atmospheric
methane monitor sensor.
