Tech Talk Blog

Gamma Radiation Effects on Polymers: Part 1

Posted by Frank Hild

October 21, 2009

Gamma Radiation is commonly used to sterilize polymer devices. But some polymers do not hold up well to this form of sterilization.

The following plastics cannot be sterilized by radiation:

* Polyacetals (turns to dust)
* Polyacetals(turns to dust)
* Polypropylene (unstabilized)
* Teflon (turns to wax)

Polypropylene Syndrome

* Natural unstabilized PP undergoes a slow degradation process after irradiation where over two years the elongation may drop from 600% to zero and parts will shatter
* PP is both crosslinked and scissioned
* Embrittlement and discoloration can occur
* Radiation stable PP is available


* Polyethylene is predominantly crosslinked but acceptable to irradiation
* PE can be stabilized to make it gamma stable

If you are unsure if your material will hold up to this sterilization technique, please visit the TriStar Plastics Corp. website for contact information.

Topics: Surface Modification