Biological indicators, tools to verify the effect of sterilisation processes - position paper prepared on behalf of group 1 (biological methods and statistical analysis).

Biological indicators (BIs) are test systems containing viable microorganisms (usually spores of bacteria) providing a defined challenge to a specified sterilisation process. General chapter 5.1.2 of the European Pharmacopoeia [1] (Ph. Eur.) sets specifications for BIs and gives some guidance for their use. As shown in this text, the approach followed by Ph. Eur. as well as by ISO standards is outdated and could create nowadays some confusion among the users of the pharmacopoeia. It is the objective of this paper to provide the theoretical background of BIs as tools for the design and qualification of reliable moist heat sterilisation processes. The principles laid down in this article will form the basis of a future draft on a revised chapter on BIs in Pharmeuropa.