Which DOT hazard class corresponds to flammable liquids?

Which DOT hazard class corresponds to flammable liquids?

• A. Class 2.
• B. Class 6.
• C. Class 3.
• D. Class 8.

Answer: (C)

The main idea is how the DOT groups hazards by the fire risk a material presents during transport. Flammable liquids are placed in the class defined by a fire hazard that arises from ignitable vapors, which is determined by their flash point. If a liquid has a flash point at 60°C (140°F) or below, it falls into this category because its vapors can ignite at relatively low temperatures. That’s why common solvents like gasoline and acetone are included here—they readily give off vapors that can ignite. The other hazards mentioned correspond to different dangers—gases, toxic materials, and corrosives—so they are not the same category as flammable liquids. Therefore, flammable liquids belong to Class 3.

The main idea is how the DOT groups hazards by the fire risk a material presents during transport. Flammable liquids are placed in the class defined by a fire hazard that arises from ignitable vapors, which is determined by their flash point. If a liquid has a flash point at 60°C (140°F) or below, it falls into this category because its vapors can ignite at relatively low temperatures. That’s why common solvents like gasoline and acetone are included here—they readily give off vapors that can ignite. The other hazards mentioned correspond to different dangers—gases, toxic materials, and corrosives—so they are not the same category as flammable liquids. Therefore, flammable liquids belong to Class 3.