Only electrical equipment that is approved by MSHA under the applicable requirements of 30 CFR parts 18 through 28 or approved under 30 CFR part 29 contained in the 30 CFR, parts 1-199, edition, revised as of July 1, 1999, shall be used underground, except for submersible sump pumps.
[64 FR 43283, Aug. 10, 1999]