A newly restored pre-vacuum steam sterilizer has to be tested before use. How many PCDs are required for Qualification Testing before the machine can be used?

The required number of Process Challenge Devices (PCDs) for qualification testing of a newly restored pre-vacuum steam sterilizer is indeed three consecutive Biological Indicators (BIs) and three consecutive DARTs in an empty chamber. This testing is crucial to ensure that the sterilizer is functioning properly and achieving the necessary sterilization parameters before it is put into operation.

Conducting three consecutive BIs verifies that the sterilization process can reliably reduce the microbial load to a safe level, as the BI contains viable spores that are resistant to the sterilization process. This is an essential part of validating the sterilizer’s capability to achieve sterility under the specified conditions.

The inclusion of three DART (Dynamic Air Removal Test) units in the testing regimen helps ascertain the efficacy of air removal in the pre-vacuum cycle, which is critical for the sterilization process. Ensuring proper air removal is necessary to achieve the correct conditions inside the sterilizer for effective steam penetration and impact.

Testing in an empty chamber is essential at this stage, as it provides a baseline for the machine’s performance without the variables introduced by the presence of actual sterilization loads. This means that the sterilizer's performance can be assessed under ideal conditions before being validated with actual items