Practical problems in radiation sterilization of medical devices made from plasticized PVC

The following three methods for sterilizing medical devices made from plasticised PVC are used in the Netherlands. 1. sterilization by steam, steam-air or superheated water. 2. sterilization by electron beam or gamma irradiation. 3. ethylene oxide sterilization. IV-bags, blood bags and other bag types for similar applications made from plasticized PVC are mostly sterilized by steam-air or super heated water, especially when filled or partly filled containers are considered. More complicated products or products with components that cannot resist steam sterilization of 1210C are sterilized by ethylene oxide or irradiation. These last two methods also are favoured for sterilizing empty bags where sticking of the surfaces at the sterilization temperature creates a serious handicap. Moreover, steam sterilization may cause a permanent opacity of some plastics. However, we have to add that due to developments in formulations steam sterilization of empty bags is going to be of an increasing importance. proven carcinogenity of the gas ethylene oxide, difficult deaeration and retention of the gas in plasticized PVC has increased the demand for better radiation resistant plastics as an alternative for steam sterilization. (author)