30 CFR § 57.22310
Electrical cables (I-C mines).
Electrical cables used to power submersible sump pumps shall be accepted or
approved by MSHA as flame resistant, or be installed in continuous metal
conduit or metal pipe. The ends of such conduit or pipe shall be sealed to
prevent entry of explosive gas or dust.
[57 FR 61223, Dec. 23, 1992]