Astramed uk Bowie & Dick Test Packs are pre-assembled, single use test packs designed to evaluate the performance of the air removal system of pre-vacuum assisted sterilizers in compliance with EN 285 and operating at 134°C and 3.5 minutes.
An indicator sheet printed with water based, non-toxic chemical indicator is places in the center of each pack. The uniform color change of the indicator after steam sterilization indicates that all air was removed and replaced by steam.
The backside of the indicator sheet contains fields to be filled out and it can be kept as a permanent record for traceability purposes.
Interpreting the Test Results
“It’s the color change that tells you the steam is penetrating the test pack and pulling all the air out of the autoclave,” according to Gillingham.
A successful Bowie-Dick Test is very evident based on the color change of the thermochormatic paper within the test pack. If the thermochromatic paper turns completely black, then the steam has penetrated the load and the autoclave is operating correctly.
Lack of or a partial color change indicates an unsuccessful Bowie-Dick Test cycle. “If the color hasn’t completely changed, it means something hasn’t worked correctly,” said Gillingham.
bowie dick test
Common Causes for Failure of a Bowie-Dick Test
Cause of Failure Description Possible Solution
Air Leak If air is able to leak into the autoclave chamber, the steam will be unable to penetrate the load to the point of total sterilization. Run a Vacuum Leak Test to further determine if an air leak exists or not.
Unwanted Condensation Occasionally condensation will get trapped in the jacket of the autoclave, which can lead to cold spots at the base of the autoclave. This could also indicate a wet-steam issue. Check the steam traps on the autoclave. Check steam quality and wetness.
Faulty Test Pack From time to time, a Bowie-Dick Test pack can be faulty. Check the expiration date and make sure the packs are being stored in the proper environment.
No Warm-Up Cycle A warm-up cycle allows the sterilizer chamber and jacket to reach temperature. Run a 5 minute sterilization cycle prior to running the Bowie-Dick Cycle.
Incorrect Procedures Test packs work under very specific conditions. Test packs should be placed in an empty chamber directly over the drain on the bottom rack or shelf. They are designed for use at 270°-273°F (132°-134°C).
Next Steps after a Bowie-Dick Test
A successful Bowie-Dick Test means you can begin sterilizing loads with a prevacuum cycle. Meanwhile, a failed Bowie-Dick Test means further testing is required. If none of the above solutions (see table) work then both the autoclave and the utilities should be checked. The autoclave should not be used with any confidence until the test is repeated with a passing result.