Which DOT hazard class corresponds to flammable liquids, and provide an example?

• A. Class 2 Gases; Example: Propane.
• B. Class 4 Flammable solids; Example: Matches.
• C. Class 8 Corrosives; Example: Sulfuric acid.
• D. Class 3 Flammable liquids; Example: Gasoline.

Answer: (D)

Flammable liquids are grouped under Class 3 because the key hazard is a low flash point: these liquids can ignite at relatively low temperatures when exposed to an ignition source. The DOT defines flammable liquids as those with a flash point at or below 60°C (140°F), which is why gasoline—a liquid that ignites readily at modest temperatures—is the classic example. This classification differentiates liquids like gasoline from other material types: a gas such as propane is classified as a gas (Class 2) due to its gaseous state at room conditions; a solid like matches is categorized as a flammable solid (Class 4) because the hazard lies in the solid material that can catch fire; and a corrosive liquid like sulfuric acid is Class 8 because its primary hazard is corrosivity to skin and metal, not flammability.