Section 392.50 - Ignition of fuel; preventionNo 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, 12/25/1968, as amended at 60 FR 38747, 7/28/1995