Toxicity is determined by a laboratory procedure called the

The Toxicity Characteristic Leaching Procedure (TCLP) is an important laboratory test designed to assess the potential hazard that certain waste materials pose to the environment, specifically in terms of leaching toxic substances into groundwater. This method simulates conditions that might occur in a landfill setting, helping to identify whether a waste material is hazardous based on the concentration of certain contaminants that leach out when the material is subjected to various conditions.

By performing the TCLP, waste samples are treated with a solution to mimic the environmental conditions present in a landfill. The leachate is then analyzed for specific metals and other toxic compounds. If the concentration of these contaminants exceeds established regulatory thresholds, the waste is classified as hazardous according to the Resource Conservation and Recovery Act (RCRA). This classification is vital for ensuring proper waste management and environmental protection.

The other options listed do not refer to the established method for determining toxicity in waste material. EPA Method 012, Method Sixteen, and landfill toxicity screening do not accurately reflect the standardized process used to evaluate the leachate's toxic potential, highlighting the significance of TCLP in hazardous waste determination.