Biological indicators for sterilisation in an isolator

Biological Indicators (in general 10⁶ spores inoculated on a physical medium) are used, beyond the validation of core terminal sterilisation processes, for the development and verification of bio-decontamination cycles for isolators that include the atmosphere and surfaces.

This type of bio-decontamination is mainly performed using vapours of peracetic acid or hydrogen peroxide (H₂O₂) as discussed in the present contribution.

This use raises problems as to the choice of the strain of bacteria, its medium and the reliability / reproducibility of its fabrication.

Having reviewed the various techniques for implementation of H₂O₂ vapours, this presentation is intended to examine the “why”, “where” and “how” issues involved in using biological indicators on isolator validation/qualification and highlights the problems that need to be avoided.