Which hazard descriptor would be used for a substance capable of exploding?

• A. Spontaneously Combustible
• B. Non-flammable compressed gas
• C. Radioactive substance
• D. Explosive

Answer: (D)

Hazard descriptors signal the main danger a substance poses. If a material can explode, the descriptor used is Explosive because it communicates the possibility of a rapid, violent release of energy that creates a blast, shock wave, and debris. This is the primary risk that drives how it should be stored and handled to prevent initiation or confinement. The other options describe different hazards—Spontaneously Combustible means it can ignite on its own due to heat, a Non-flammable compressed gas is a gas stored under pressure that doesn’t burn, and a Radioactive substance mainly presents radiation risks. None of those describe an explosive blast, so Explosive is the correct descriptor.