Which hazardous-material classes are subject to restrictions against overhanging or open-tailgate loads?
Correct answer: D – All of these
Class 1 explosives must generally remain within the vehicle body or its horizontal outline, with the tailgate closed and secured. Class 4 and Class 5 loads generally must be contained within a covered vehicle body with the tailgate secured. The detailed rules include limited exceptions for qualifying packaging, water-tight bulk containers, and certain local pickup-and-delivery operations.
Source: Ohio Commercial Driver License Manual — § 9.4.1, “Use Closed Cargo Space”, 49 CFR § 177.835(h) – Class 1 (explosive) materials, 49 CFR § 177.838(a) – Class 4 (flammable solid) materials, Class 5 (oxidizing) materials, and Division 4.2 (self-heating and pyrophoric liquid) materials


