Division 5.1 refers to which category of substances?

• A. Oxidizing Substances
• B. Organic Peroxides
• C. Inorganic Peroxides
• D. Flammable Gases

Answer: (B)

Division 5.1 identifies oxidizing substances. These materials release oxygen or create conditions that support and accelerate combustion, which is why they are treated as a distinct hazard and require specific handling and packaging. Organic peroxides, by contrast, belong to a different subdivision (they are 5.2) and consist of organic compounds with peroxide groups that can decompose violently on their own. That difference in behavior and risk profile is why Division 5.1 points to oxidizing substances rather than organic peroxides.