The proposal comes in the wake of the Chevron 2012 pipe rupture and fire in the Bay Area.
They can overheat and melt and thus present fire and burn hazards.
A proposed rule from the agency offers two options: driving with a stable vision condition for at least a year or no specific amount of CMV driving experience required.
The study, published in the Journal of Food Protection, points to a lack of safe procedures for raw ground beef and leafy greens in many restaurants.