A comparative study on the performance of asbestos-free depth-filters for removal of pyrogens from infusion fluids

Three asbestos-free depth-filters were compared with traditionally used asbestos-containing depth-filters for chemical integrity, physical integrity and pyrogen retention. With chemical and physical integrity only minor differences between the various filter types were seen. One asbestos-free depth-filter, based on charcoal, showed poor pyrogen-retention; this might be due to a high flow rate used. Asbestos-free depth-filters based on kieselguhr or on a mixture of kaolin and alumina proved to be good alternatives; these filters have proved to be suitable for the removal of pyrogens from electrolyte- or carbohydrate-containing infusion fluids.