Division 4.3 hazard covers which type of materials?

Division 4.3 hazard covers which type of materials?

• A. Division 4.3 hazard applies to oxidizers.
• B. Division 4.3 hazard covers toxic gases.
• C. Division 4.3 hazard covers dangerous when wet materials (magnesium powder).
• D. Division 4.3 hazard covers radioactive materials.

Answer: (C)

Division 4.3 is for materials that are dangerous when wet—substances that react with water to release flammable gases or heat. Magnesium powder is a classic example because it reacts vigorously with water, producing hydrogen gas that can ignite. Other hazard types sit in different divisions: oxidizers are not in 4.3, toxic gases are a 2.3 concern, and radioactive materials are in 7. The key idea is that 4.3 covers materials that become hazardous when moisture is present, so magnesium powder fits this category due to its moisture-triggered reaction. Handle and store these materials dry, and avoid water to combat any incident involving them, using appropriate dry extinguishing methods if needed.

Division 4.3 is for materials that are dangerous when wet—substances that react with water to release flammable gases or heat. Magnesium powder is a classic example because it reacts vigorously with water, producing hydrogen gas that can ignite. Other hazard types sit in different divisions: oxidizers are not in 4.3, toxic gases are a 2.3 concern, and radioactive materials are in 7. The key idea is that 4.3 covers materials that become hazardous when moisture is present, so magnesium powder fits this category due to its moisture-triggered reaction. Handle and store these materials dry, and avoid water to combat any incident involving them, using appropriate dry extinguishing methods if needed.