from Hideharu Shintani and Gerald McDonnell writing in Prions: Current Progress in Advanced Research:
Several inactivation procedures to prion and endotoxins are reported so far. Most of these methods are not applicable to re-usable medical devices due to failure of achievement of material and functional compatibility. Gas plasma inactivation procedure for prion and endotoxin was studied and attain both sterility assurance level (SAL) of 10-6 and material and functional compatibility in ease.
Further reading: Prions: Current Progress in Advanced Research