DOT Hazard Class 4 consists of which type?

DOT Hazard Class 4 consists of which type?

• A. Flammable liquids
• B. Flammable solids
• C. Oxidizers
• D. Poisons

Answer: (B)

The key idea is that DOT Hazard Class 4 is defined for flammable solids—solid materials that can ignite readily, often through friction, heat, or contact with moisture. This is why the correct description is flammable solids. Flammable liquids belong to Class 3 because they are liquids that burn, not solids. Oxidizers are a different category (Class 5.1) because they release or support the reaction with oxygen, and poisons are Class 6 due to their toxic effects. So materials described as flammable solids, like certain metal powders or matches, fit Class 4, confirming why that choice is the best answer.

The key idea is that DOT Hazard Class 4 is defined for flammable solids—solid materials that can ignite readily, often through friction, heat, or contact with moisture. This is why the correct description is flammable solids. Flammable liquids belong to Class 3 because they are liquids that burn, not solids. Oxidizers are a different category (Class 5.1) because they release or support the reaction with oxygen, and poisons are Class 6 due to their toxic effects. So materials described as flammable solids, like certain metal powders or matches, fit Class 4, confirming why that choice is the best answer.