No driver or any employee of a motor carrier shall:

(a) Fuel a commercial motor vehicle with the engine running, except when it is necessary to run the engine to fuel the commercial motor vehicle;

(b) Smoke or expose any open flame in the vicinity of a commercial motor vehicle being fueled;

(c) Fuel a commercial motor vehicle unless the nozzle of the fuel hose is continuously in contact with the intake pipe of the fuel tank;

(d) Permit, insofar as practicable, any other person to engage in such activities as would be likely to result in fire or explosion.

[33 FR 19732, Dec. 25, 1968, as amended at 60 FR 38747, July 28, 1995]