What is defined as a hazardous waste?

• A. Any discarded liquid, semisolid, solid or containerized gaseous material.
• B. A non-hazardous solid
• C. A material that decomposes quickly
• D. A material that is not discarded

Answer: (A)

Hazardous waste is defined by its status as waste that has been discarded and could pose a risk to human health or the environment. This idea applies across all physical forms, so any discarded material—whether liquid, semisolid, solid, or containerized gaseous material—falls into the category of waste that may require hazardous management. The other statements describe materials that aren’t discarded or properties that don’t define waste status, so they don’t capture the essential notion of hazardous waste.