It is a hazardous waste characteristic which applies to wastes that have the potential to contaminate groundwater if improperly disposed of. These materials are regulated as hazardous waste due to their potential to leach out specific toxic substances in a landfill.

• A. Toxicity
• B. Reactivity
• C. Ignitability
• D. Corrosivity

Answer: (A)

The key idea is the toxicity characteristic, which targets wastes that could contaminate groundwater if they leach out of a landfill. If a waste contains certain toxic constituents that can be released into leachate at harmful concentrations, it is regulated as hazardous under this category. Regulatory tests, like the leaching procedure that mimics landfill conditions, determine whether those substances would exceed safe limits; if they do, the waste is classified hazardous because of its potential to pollute groundwater. This is different from ignitability (risk of fire), corrosivity (extreme pH that can corrode containers), or reactivity (unstable or explosive behavior).