CA28140-037 28143-014 28140-160 28140-037. Membrane Discs with GHP Membrane, Pall Laboratory. Pall GHP Polypropylene membrane will be discontinued effective October 31st, 2019. This discontinuation affects devices including Membrane Discs, Syringe Filters, Filter Plates, and Centrifugal Devices. Membrane disc filters, GH Polypro (GHP) | VWR