The Bowie Dick test can be run under the following times at 270 F for larger sterilizers except:

The Bowie Dick test is specifically designed to evaluate the efficacy of steam sterilization processes and is crucial for ensuring that air has been effectively removed from the sterilizer chamber and that steam can penetrate the test pack. Under standard conditions, the test is typically conducted at 270°F (132°C) for designated periods.

For a larger sterilizer, the Bowie Dick test can be successfully conducted for 3 minutes, 3.5 minutes, and 4 minutes. However, a duration of 4.5 minutes exceeds the recommended exposure time for this specific test in typical protocols. The test is standardized to confirm that sterilization occurs within the recommended times, and lengths of exposure longer than those established can result in erroneous readings or unnecessary complications in process validation.

Therefore, running the Bowie Dick test at 270°F for 4.5 minutes is not appropriate as it exceeds the standard timeframes, which is why this choice is identified as the exception.