What class of hazardous material includes flammable liquids?

• A. Class 1
• B. Class 2
• C. Class 3
• D. Class 4

Answer: (C)

Flammable liquids belong to Class 3 because this category is for liquids whose vapors can ignite at relatively low temperatures. The defining factor is the liquid state and its potential to produce ignitable vapors, measured by the flash point (for flammable liquids, the flash point is low enough that ignition can occur under normal handling conditions). This distinguishes them from other hazard types: gases are Class 2, which are hazardous primarily as a contained vapor or gas; explosives are Class 1, involving energetic detonation or rapid release of energy; and flammable solids are Class 4, which are solids that can ignite easily. So the designation of flammable liquids as Class 3 reflects their liquid form and ignition risk, guiding appropriate handling, labeling, and emergency response.