Toxicity Characteristic Leaching Procedure (TCLP) is an analytical test designed to determine the leaching potential in a landfill for hazardous organic and inorganic contaminants. The Whatman TCLP Filter is a binder-free borosilicate glass microfiber filter with a particle retention rating of 0.6 µm to 0.8 µm,as specified by EPA Method 1311. These acid-treated low metal filters are available in 47, 90, 110, 125, 142 and 150 mm diameters. The 90 mm filter is required for volatile samples and use with a Zero Headspace Extractor. The 142 mm filter is typically used with nonvolatile samples in an approved jar.