Zeus has a long and successful history in medical markets around the world from the simplest laparoscopic instruments to the most complex multi-channel catheters. When gamma sterilization was developed, Zeus was one of the first fluoropolymer extruders to offer information on this increasingly popular sterilization method.
FEP, PFA, ETFE, PEEK, PE, PVDF, and polyimides are just some of the resins extruded by Zeus. Each of these resins can tolerate gamma radiation to varying degrees making them suitable for certain medical and analytical applications requiring sterility. PTFE, however, does not stand up to gamma radiation exposure well enough to be sterilized. (PTFE can be sterilized by other methods). For details regarding the particular resin that you are working with, please contact a Zeus Technical Account Manager or view our Sterilization Methods for more information.
Gamma Radiation Sterilization
Gamma rays are a form of electromagnetic radiation emitted by radioactive materials; they are similar to x-rays but are high in energy. Today, the primary sources of industrial use gamma radiation are cobalt 60 (60Co) and cesium 137 (137Cs) which emit gamma rays during their radioactive decay. Gamma rays are a penetrating form of radiation which easily pass through even highly dense materials – including plastics. Gamma rays break the covalent bonds of DNA killing bacteria and other microbes exposed to the radiation.
The penetrating nature of gamma rays means that no area of the item being sterilized is left with uncertainty regarding sterilization. Items can also be sterilized in bulk via gamma radiation. Most importantly, however, is that items exposed to gamma radiation do not acquire radioactivity themselves, that is, they do not become radioactive simply from being exposed to gamma radiation. These inherent qualities of gamma sterilization make this method highly reliable and safe.
Gamma sterilization has been found to be a cost effect method and can be performed at comparatively low temperatures (less than 100 °F / 38 °C). The item being sterilized is simply placed near the gamma source until the required dose has been absorbed. Items sterilized via gamma exposure can be used immediately after sterilization. Today, many of the common polymers used in medical devices and packaging are naturally radiation stable so that they can be gamma sterilized.