Biological Indicators and Process Challenge Devices for Nitrogen Dioxide Sterilization

Few data have been published regarding the use of biological indicators (BIs) for nitrogen dioxide (NO₂) sterilization. This article presents findings from a comprehensive series of studies conducted to assess BI performance across common circumstances: transport, shelf life, integration within self-contained BIs (SCBIs), poststerilization handling, and incubation. The results showed that BIs retained their performance characteristics after transport and for up to 12 months of storage postmanufacture. During sterilization, SCBIs functioned reliably as external process challenge devices (PCDs) for NO₂ processes. Following sterilization, external PCDs could be held for up to 48 hours prior to activation and incubation without compromising results. BI growth outcomes can be finalized in as little as 42 hours, enabling timely product release. These findings confirmed the reliability of BIs for NO₂ sterilization and support their use in validation and routine monitoring of NO₂ sterilization processes.