The CPFA efficacy on bilirubin adsorption is based on hydrophobic polystyrene-divinylbenzene copolymer matrices of the resin cartridge that have mean pore sizes of 30 nanometres. Harm et al. reported that the hydrophobic polystyrene-divinylbenzene copolymer of CPFA resin cartridge (type B copolymer: mean diameter 128 micron, pore size 30 nanometres and surface area of 700 m2/gr of resin) binds higher amount of bilirubin than the amount of bilirubin bound with the other kinds of polystyrene-divinylbenzene copolymer matrices tested (type A copolymer: mean diameter 120 micron, pore size 15 nanometres and surface area of 900 m2/gr of resin; type C copolymer: mean diameter 37 micron, pore size 100 nanometres and surface area of 200 m2/gr of resin).