The federal smoking rule also reaches an empty tank motor vehicle that was required to be marked or placarded for the Class 3, flammable or Division 2.1 flammable gas material it last carried. For a loaded vehicle, what does the rule forbid, and which materials does it name?

Explanation

No person may smoke or carry a lighted cigarette, cigar or pipe on or within 25 feet of a motor vehicle containing Class 1 materials, Class 5 materials, or flammable materials classified as Division 2.1, Class 3, Divisions 4.1 and 4.2. The rule reaches the lighted article itself, not just the act of smoking, so carrying a lit cigarette past the vehicle breaks it as surely as standing there smoking does. It also follows the vehicle after the cargo is gone in one case: an empty tank motor vehicle that was used to transport Class 3, flammable materials or Division 2.1 flammable gases, and that was required to be marked or placarded when so used, is covered too. The wrong options each move one element, confining the rule to the cab, inflating the distance to every placarded load, or cutting the list of classes down to explosives alone.

Source: 49 CFR 397.13