I think NESC [National Electric Safety Code IEEE/ANSI C2] will be suitable for it.
See:
NESC Rule 354:
2. Radial separation of supply and communications cables or conductors from steam lines, gas, and other lines that transport flammable material shall be not less than 300 mm (12 in) and shall meet Rule 353.
3. Supply circuits operating above 300 V to ground or 600 V between conductors shall be so constructed, operated, and maintained that when faulted, they shall be promptly de-energized initially or following subsequent protective device operation (phase-to-ground faults for grounded circuits, phase-to-phase faults for ungrounded circuits).