leachtesten

Leachtesten, or leaching tests, are standardized procedures that measure how much of a substance can be released from a solid material into a liquid under defined conditions. They are used in waste management, environmental engineering, geology, and materials testing to assess environmental risk, regulatory compliance, and product safety.

Common examples include the Toxicity Characteristic Leaching Procedure (TCLP) used in the United States, and the Synthetic Precipitation Leaching Procedure (SPLP) that simulates rainfall. European and other jurisdictions use tests such as the EN 12457 series and national standards. The methods differ in leachant composition, contact time, agitation, and test duration.

In a typical procedure, a sample is prepared (ground or crushed to a specified size), a leachant is chosen, and the material is contacted under defined conditions. After the exposure period, the liquid is filtered and analyzed for target contaminants using analytical techniques such as ICP-MS, IC, or atomic absorption spectroscopy. Results are reported as concentrations in the leachate and are compared with regulatory limits to classify waste or assess site risk.

Limitations include that laboratory leach tests only approximate real-world conditions, and results depend on factors such as particle size, matrix, pH, temperature, and leachant strength. Leachtesten thus form one part of a broader environmental assessment framework, complemented by long-term monitoring and field studies.