ISO 11135-1:2007 specifies requirements for the development, validation and routine control of an ethylene oxide sterilization process for medical devices. Sterilization processes validated and controlled in accordance with the requirements of ISO 11135-1:2007 are not assumed to be effective in inactivating the causative agents of spongiform encephalopathies such as scrapie, bovine spongiform encephalopathy and Creutzfeld Jacob disease. Specific recommendations have been produced in particular countries for the processing of materials potentially contaminated with these agents.