A Class C vehicle is used to haul a non-hazardous liquid in a single 500-gallon tank. Is a tank endorsement required for this trip?

AAMVA CDL Manual, Section 8 (Tank Vehicles), p.8-8-1 ("A tank endorsement is also required for Class C vehicles when the vehicle is used to transport hazardous materials in liquid or gas form in the above described rated tanks."); 49 CFR 383.5 defines "ta

This distinction matters because the rule is different for Class C vehicles than for Class A or B: the hazardous-material condition only applies to Class C. A driver who misunderstands this could wrongly believe every large tank load needs the endorsement, or wrongly skip it when hauling hazardous liquids.