Infection prevention and control guidelines

10. Reprocessing reusable medical devices

Running the sterilisation cycle

      1. Running the sterilisation cycle

Last revised: 18 Aug 2023

Running the sterilisation cycle

For sterilisers that produce printouts, the paper position and ink levels must be checked before running each cycle to ensure the data are recorded.

Processing time

The time (and temperature, if more than one option) selected for sterilising a load is a critical factor in ensuring sterility of the load. The processing time is the sum of the penetration (equilibration) time and the holding time.

Often manufacturers pre-set the processing time on sterilisers. These times must be checked during the validation process when the steriliser is commissioned, and altered if necessary to ensure adequate time at temperature to kill all microorganisms.

The penetration time is the time it takes for the hardest to reach part of the load to achieve the required temperature, once the chamber has reached that temperature). It is determined at the time of validation using a ‘challenge’ pack.

The holding time is the time the load must be held at the sterilising temperature, and includes a safety factor. The holding time for the cycle will depend on the type of items loaded. It must be determined by the steriliser technician during validation procedures for the steriliser.

Drying time

The validation process determines the minimum drying time for cycles, based on the challenge load(s).

Heat distribution

Heat distribution studies are not required for small steam sterilisers (< 60 L) and may not be effective in identifying a ‘cold spot’ in a small benchtop steriliser).

For large sterilisers, a heat-distribution study is required to ensure that monitoring reflects the temperature in the coolest part of the chamber. This study is only required once and may be available either from the manufacturer, a previous validation, or can be determined by the service technician.

This can be checked during routine calibration and should not be an additional expense.