ISO 11138-1:2017 specifies general requirements for production, labelling, test methods and performance characteristics of biological indicators, including inoculated carriers and suspensions, and their components, to be used in the validation and routine monitoring of sterilization processes. ISO 11138-1:2017 specifies basic and common requirements that are applicable to all parts of ISO 11138. Requirements for biological indicators for particular specified processes are provided in the relevant parts of ISO 11138. If no specific subsequent part is provided, this document applies. NOTE National or regional regulations can apply. ISO 11138-1:2017 does not apply to microbiological test systems for processes that rely on physical removal of microorganisms, e.g. filtration processes or processes that combine physical and/or mechanical removal with microbiological inactivation, such as use of washer disinfectors or flushing and steaming of pipelines. This document, however, can contain elements relevant to such microbiological test systems.