When permanent splices in trailing cables are made, they shall be:
(a)
Mechanically strong with adequate electrical conductivity and flexibility;
(b)
Effectively insulated and sealed so as to exclude moisture; and
(c)
Vulcanized or otherwise treated with suitable materials to provide flame-resistant qualities and good bonding to the outer jacket.
(d)
Made using splice kits accepted or approved by MSHA as flame resistant.
Code of Federal Regulations
[35 FR 17890, Nov. 20, 1970, as amended at 57 FR 61223, Dec. 23, 1992]