Establishing a minimum incubation time for biological indicators

There is no universally recognized method to establish an acceptable minimum incubation time (MIT) of less than seven days for biological indicators (BI) used to monitor the effectiveness of sterilization processes. A method to qualify a reduced incubation time of less than seven days was published by FDA in the Center for Device and Radiological Health Guide for the validation of Biological Indicator Incubation Time in 1986. The international community, however, has been reluctant to accept this method due to the lack of published results to support the chosen test requirements and acceptance criteria. In 2007, the ISO/TC198 Working Group 4 (WG4), Biological Indicators, initiated a New Work Item Proposal (NWIP) to develop an ISO Technical Specification that would contain a method for validation of an MIT for BIs. This article is a result of the ad hoc committee's efforts and proposes a method to establish an MIT for BIs.