Smoking is prohibited while loading or unloading which group of hazardous materials?
Correct answer: C – Class 1, Division 2.1, and Classes 3, 4, and 5
Smoking is forbidden on or around a vehicle while loading or unloading Class 1 explosives, Division 2.1 flammable gas, Class 3 flammable liquids, Class 4 flammable solids, or Class 5 oxidizers. Fire, matches, and other flames must also be kept away. The rule does not include every material within Class 2.
Source: Utah Commercial Driver License Handbook — § 9.4.1, “General Loading Requirements”, 49 CFR § 177.834(c)–(d) – General requirements

