Market forces are increasingly pushing manufacturers and system integrators of polymer-based products to diversify their options for sterilization methods. This needed diversification in options for sterilization modality must involve the irradiation modalities of X-ray and electron beam (e-beam).  Although the technology of these two irradiation modalities is mature and dependable, the lack of data on resulting polymer effects, and the lack in number of facilities, are two of the main impediments. In an effort to fill these data, knowledge and tool gaps, an international collaboration team was formed in 2018. This “Team Sam Nablo”, currently has 13 active member organizations. This presentation summarizes the team’s ongoing projects, including the results of studies comparing the differences in radiation effects between gamma, X-ray and e-beam irradiated products.

So far, the team has tested 10 polymer devices from five manufacturers (involving near 30 distinct polymers) to cobalt-60, e-beam and X-ray fields to determine the influence of absorbed dose and irradiation modality on the effects observed. The team is also performing comprehensive studies to elucidate the influence of dose rate and oxidative environments on these effects in polymers.

One general conclusion from the testing is that many polymer properties are affected by the high radiation dose levels involved with sterilization, but differences in effects between the three radiation modalities are generally minor. The most profound influence of irradiation modality observed was an increase in yellowing in certain polymers such polycarbonate (for the X-ray modality) and polyvinyl chloride (for the e-beam modality).  The data has resulted in eight manuscripts, soon to be published.