Tolerance of biological indicators refers to the ability of their microorganisms to withstand various sterilization procedures. Generally speaking, the tolerance of biological indicators is expressed by D value. D value refers to the sterilization time or sterilization dose required to kill 90% of the test microorganisms. The main quality parameters of biological indicator include the spore total, D value, the survival time and the killing time.

This Guidelines is used to guide the determination of the tolerance of biological indicators and relevant quality parameters. The Guidelines can also be used to determine the tolerance of contaminating microorganisms in the production process.