Total Filtration Services Filters Clean Pak filters are made with dual layer high loft synthetic media for maximum dust holding capacity. The upstream layer is a meltdown facing that protects the final filter layer and prevents erosion. The final filter layer is high loft melt blown synthetic fibers that provide high efficiency and high dust holding capacity with low resistance. High Loft Synthetic Media Unusually Large Product Selection Rugged Construction Fail Safe Pocket Attachment Total Pocket Inflation Select From Five Efficiencies Bag Filter, Merv 15, Downstream Gasket Pack of 4 Filters Used filters must be disposed of properly, since they may be classified as a hazardous waste. The federal law that covers disposal of waste is the Resource Conservation and Recovery Act (RCRA). Lead captured by the filter may be recycled. Recycling activities are exempt from RCRA regulations. If you do not recycle the lead in the filters, the filters should be tested using the Toxicity Characteristic Leaching Procedure (TCLP). If the TCLP results are less than 5 parts per million (ppm), the filters can be disposed of as normal solid waste (trash). If the TCLP results are above 5 ppm, the filter must be disposed of as hazardous waste through a licensed hazardous waste company. You should keep all test results and shipping manifests in a file so you can demonstrate that the waste has been disposed of properly.