January 8, 2020
To fully answer why this test is still important today, we must first understand why it is important to remove air from the sterilizer. Air within a steam sterilizer is often referred to as a non-condensable gas (NCG). As the name indicates, non-condensable gases do not condense when touching a colder item. These gases act like a shield between the steam and the item, potentially shielding bacteria and preventing proper sterilization.
Even todays sterilizers are not capable of detecting NCG because it could be hiding anywhere in the chamber. Sensors would need to be placed within the packs exactly where the NCG would either be trapped or collected in order to detect it. This is not possible and supports why air-removal tests are still very relevant to todays modern sterilizers for autoclave testing. The Vacuum Leak Test programmed on your autoclaved only measures the integrity of the sealed pressure vessel and associated piping to assure air is not being admitted to the sterilizer during the vacuum draw downs.
In addition to air-removal, modern Bowie-Dick Tests such as the VERIFY Bowie-Dick Test Pack provide a critical control for sterilizer performance and verification of steam quality. It ensures the sterilizer can provide the validated preconditioning required, and aid in detection of steam quality that could interfere with sterilization of complex instrumentation.