30 CFR § 18.1
The regulations in this part set forth the requirements to obtain MSHA:
Approval of electrically operated machines and accessories intended for use
in gassy mines or tunnels, certification of components intended for use on or
with approved machines, permission to modify the design of an approved
machine or certified component, acceptance of flame-resistant hoses, sanction for use of experimental machines and accessories in
gassy mines or tunnels; also, procedures for applying for such approval,
certification, acceptance for listing.