Purtrex depth cartridge filters are a patented thermally bonded filter for all-around industrial use in plating, chemical filtration, and potable water. Purtrex is an exceptional value for applications where long life, high purity, and low change-out frequency are desired. Exceptional value for general applications Progressive graded density captures particles throughout the entire filter No surface blinding (surface blinding causes flow reduction, which increases filter change outs) Inert material means broad chemical compatibility Exceptional dirt-holding capacity Pure 100% polypropylene construction No wetting agents, solvents, antistatic agents, or binders Incinerates into trace ash with no hazardous volatiles for easy disposal Made in the USA Certifications U.S. FDA 21CFR 177.1520 food contact requirements Article 3 of the EU Framework Regulation No. 1935/2004/EC safety requirements EU Plastics Regulation No. 10/2011 (may be used as intended in compliant EU Member states) USP class VI-121C Plastics criteria NSF 42 and 61 criteria ISO 9001 criteria