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Bowie-Dick (DART) Test (CRCST Domain 4: Sterilization Process)
AI fact-checked, not reviewed by a certified technician. Spot an error? Report it. Report an error Outline refs: Sec4 III.A, Sec4 III.B.
- The Bowie-Dick (DART) test checks air removal in dynamic-air-removal (pre-vacuum) steam sterilizers. [AAMI ST79; HSPA outline Sec4 III.B]
- Run it daily, in an empty chamber, before the first processed load. [AAMI ST79 (verify)]
- A non-uniform color change is a failure: do not use the sterilizer until the problem is fixed. [AAMI ST79; sterilizer IFU]
- It is not a sterility test and does not replace biological indicators. [AAMI ST79]
Steam can only sterilize surfaces it touches. In a dynamic-air-removal (pre-vacuum) sterilizer, a vacuum pump pulls air out of the chamber and the load in a series of pulses during the conditioning phase. If air remains, because of a leak, a faulty vacuum system or poor steam quality, it forms pockets that steam cannot penetrate. The Bowie-Dick type test, also called a DART (Dynamic Air Removal Test), is designed to detect exactly that problem.
How it is run
The test pack contains a Type/Class 2 specific-test chemical indicator sheet inside a challenge material. It is placed in an empty chamber, typically on the bottom shelf near the drain unless the manufacturer says otherwise, and run in a cycle designed for the test. AAMI guidance calls for running it each day the sterilizer is used, before the first processed load. Gravity-displacement sterilizers do not use a vacuum air-removal stage, so the Bowie-Dick test does not apply to them.
Reading the result
A pass is a uniform color change across the sheet. A lighter area or uneven color, often in the center, means air was not adequately removed. A failed test means the sterilizer must not be used for patient loads. Follow policy: repeat the test if allowed, and if it fails again, take the sterilizer out of service, report it for repair and document everything.
Related checks
A vacuum leak test checks whether air leaks into the chamber during vacuum phases; many sterilizers run it automatically. After installation, relocation or major repair, qualification testing commonly includes three consecutive Bowie-Dick tests and three consecutive BI process challenge device cycles in an empty chamber, all of which must pass before the sterilizer returns to use.
How the CRCST tests this
Expect questions on timing (daily, empty chamber, before the first load), which sterilizers need it, what a failure looks like and the correct response to a failure.
Practice questions
When is a Bowie-Dick type (DART) test typically run?
A. Daily, in a full load, before the first patient load in a gravity-displacement sterilizer
B. Daily, in an empty chamber, before the first load in a pre-vacuum steam sterilizer
C. Weekly, in an empty chamber, after the last load of the day in a pre-vacuum sterilizer
D. With every load that contains an implant, placed next to the biological indicator PCD
Answer: B
In a dynamic-air-removal steam cycle, the conditioning phase:
A. Removes air and preheats the load with alternating steam pulses
B. Cools the load slowly so packs do not condense when they are removed
C. Holds the load at the set temperature for the required time
D. Draws a vacuum to remove steam and dry the load after exposure
Answer: A
A gravity-displacement steam sterilizer removes air by:
A. A chemical absorber in the drain line that captures air molecules
B. Steam entering and pushing the heavier air down and out through the drain
C. Steam entering at the bottom and pushing the lighter air out the top vent
D. A vacuum pump drawing air out of the chamber in a series of pulses
Answer: B
A vacuum leak test on a pre-vacuum steam sterilizer checks:
A. Whether the chamber reaches the set temperature during exposure
B. Whether the door gasket leaks steam into the room
C. Whether steam fully penetrates a test pack in an empty chamber
D. Whether air is leaking into the chamber during the vacuum phases
Answer: D
The daily Bowie-Dick test sheet shows a non-uniform color change. What should be done?
A. Run patient loads but double the exposure time, then repeat the test tomorrow before the first load
B. Do not use it; repeat the test, and if it fails again, remove it from service and report it
C. Use it for gravity cycles only, since the Bowie-Dick tests vacuum cycles
D. Release loads if the printout shows the correct temperature, time and pressure
Answer: B
Common mistakes
- Running the test in a full load instead of an empty chamber.
- Treating a pass as proof that loads are sterile.
- Using the sterilizer after a failed test because the printout looked normal.
Resumen en español: La prueba Bowie-Dick (DART) verifica la eliminación de aire en esterilizadores de pre-vacío. Se corre diario, con la cámara vacía y antes de la primera carga. Pasa con un cambio de color uniforme; si hay zonas más claras, falla y el esterilizador no se usa hasta repararlo. No prueba esterilidad ni sustituye al indicador biológico. No aplica a esterilizadores por gravedad.
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FAQ
Do gravity sterilizers need a Bowie-Dick test?
No. The test is for dynamic-air-removal (pre-vacuum) sterilizers.
What indicator class is a Bowie-Dick sheet?
Type/Class 2, a specific-test indicator.