For effective sterilization
Whole of the material subjected to the treatment
Additional method of monitoring
Storage and use, quality checked through positive control
Risk of contamination
To ensure that the sterilization is effective, the whole load of material has to be subjected to the treatment.
Biological indicators (BIs) can be considered as part of the monitoring of the sterilization process. Their use should always be controlled to prevent contamination of the facility and product with live micro-organisms.
The manufacturer should have proper control over the storage and use of BIs. Their quality should also be checked through positive control.
Don't forget that there is a risk of contamination in case of uncontrolled handling, breakage etc.