Class 5 hazmats are what materials?

• A. Toxic Substances
• B. Acids
• C. Water Reactive Materials
• D. Oxidizers and Organic Peroxides

Answer: (D)

Class 5 hazards are materials that can cause or intensify a fire. This category covers oxidizers, which release oxygen and thereby help other fuels burn more readily, and organic peroxides, which are unstable and can decompose violently, producing heat, gas, and sometimes an explosion. Because of this tendency to fuel burning or to react violently on their own, they’re grouped separately from other hazard types.

Toxic substances belong to health hazards that affect people, not the fire chemistry, so they’re Class 6. Acids are typically corrosive materials, placed in Class 8, not Class 5. Water-reactive materials react with water to release other hazards (like gases), which is Class 4.3. So the label “oxidizers and organic peroxides” correctly describes Class 5 hazards.