Which DOT hazard class is defined as Flammable solids?

• A. Class 3: Flammable liquids
• B. Class 4: Flammable solids
• C. Class 7: Radioactive
• D. Class 9: Miscellaneous

Answer: (B)

Flammable solids are categorized under Class 4 in the DOT system. This class covers solids that can ignite through friction, heat, or moisture and may burn vigorously or even react in a way that creates a fire hazard. Recognizing that flammable solids belong to Class 4 helps you know the specific handling, packing, and labeling requirements to prevent ignition and manage the risk. In contrast, other options refer to different hazards: flammable liquids are Class 3, radioactive materials are Class 7, and miscellaneous dangerous goods are Class 9.