Highly hazardous chemicals are defined by possessing which properties?

• A. Toxic, reactive, flammable, or explosive properties
• B. Nonhazardous properties
• C. Only flammable properties
• D. Only toxic properties

Answer: (A)

Highly hazardous chemicals are defined by any property that makes them dangerous to people or the environment: they can be toxic, reactive, flammable, or explosive. Toxic means exposure can cause injury or illness; reactive means they can undergo dangerous chemical reactions or release harmful gases; flammable means they ignite easily and can start or spread fires; explosive means they can release energy rapidly, causing blasts. If a chemical has one or more of these properties, it qualifies as highly hazardous because of the significant risk it poses in handling, storage, or in an accident.

The other options don’t fit because they either limit the hazard to a single property or claim there’s no hazard at all.