Division 4.3 hazard is best described as covering which of the following?

Division 4.3 hazard is best described as covering which of the following?

• A. Oxidizers.
• B. Dangerous when wet materials.
• C. Toxic gases.
• D. Radioactive materials.

Answer: (B)

Division 4.3 hazards are substances that become dangerous when they come into contact with water. They react with moisture to release flammable gases, heat, or sometimes toxic gases, so the defining label is “Dangerous when wet.” That’s why this description fits best. Examples include calcium carbide and certain reactive metals like sodium or potassium, which must be kept dry to prevent a dangerous reaction. This category is distinct from oxidizers (which are Class 5.1), toxic gases (typically Class 2 or 6.1), and radioactive materials (Class 7).

Division 4.3 hazards are substances that become dangerous when they come into contact with water. They react with moisture to release flammable gases, heat, or sometimes toxic gases, so the defining label is “Dangerous when wet.” That’s why this description fits best. Examples include calcium carbide and certain reactive metals like sodium or potassium, which must be kept dry to prevent a dangerous reaction. This category is distinct from oxidizers (which are Class 5.1), toxic gases (typically Class 2 or 6.1), and radioactive materials (Class 7).