CHM® MPP Polypropylene membrane filters are composed of pure polypropylene with absolute pore size ratings. Because of their hydrophobic nature, the polypropylene membranes are best suited for industrial processes such as gas filtration, chemical processes and photo-resist production as well as for application in the automotive industry. Due to polypropylene is a pure hydrocarbon material, there are no disposal problems relating to halogen content with PP membrane in contrast with other hydrophobic membranes such as PVDF or PTFE. They are supplied as standard in 0.2 and 0.45 μm pore sizes, and in different diameters.