Geobacillus stearothermophilus and Bacillus atrophaeus spores exhibit linear inactivation kinetic performance when treated with an industrial scale vaporized hydrogen peroxide (VH2O2) sterilization process

Abstract

Many medical devices are supplied as sterile for safe patient care (McEvoy and Rowan 2019). The global sterilization services market is projected to reach USD 5.5 billion by 2026, growing at a compound annual growth rate (CAGR) of 6.0%, primarily driven by increasing surgical procedures, the prevalence of hospital acquired infections and increased outsourcing of sterilization services (Anon 2021, McEvoy et al. 2021). A sterilization process may be defined as a “series of actions or operations needed to achieve the specified requirements for sterility” (ISO 2018). Sterility is not an absolute; therefore, it must be predicted and expressed in terms of the probability of achieving the inactivation of microbial and other infectious agents post-sterilization treatment (McEvoy and Rowan 2019). Moreover, the underpinning sterility assurance level (SAL) is defined as the ’probability of a single viable microorganism occurring on an item after sterilization’ (ISO 2018). A sterilization process is validated whereby a pre-determined SAL is demonstrated through a series of process evaluations (McEvoy and Rowan 2019). In accordance with ISO14937:2009, microbicidal effectiveness must be established such that it is plausible to predict the probability of a defined resistant microorganism surviving exposure to a defined treatment.