Which DOT hazard class is an oxidizer, and give a typical example?

• A. Class 2 Gases; Example: Propane.
• B. Class 3 Flammable liquids; Example: Gasoline.
• C. Class 4 Flammable solids; Example: Matches.
• D. Class 5.1 Oxidizers; Example: Ammonium nitrate.

Answer: (D)

Oxidizers are substances that release oxygen or otherwise promote combustion, helping other materials burn more intensely. In the DOT system, oxidizers fall under Class 5.1. A typical example is ammonium nitrate, a common oxidizer used in fertilizers that can intensify fires or even detonate under certain conditions when paired with fuels. That makes the option describing Class 5.1 oxidizers with ammonium nitrate the best choice.

To put it in context, propane is a Class 2 gas and burns as a fuel; gasoline is a Class 3 flammable liquid; matches are a Class 4 flammable solid. None of those provide oxygen to other materials in the way an oxidizer does.