Every pre-vacuum sterilizer needs a daily air-removal check, and the Bowie-Dick test pack is the standard tool. This Type 2 indicator, built to ISO 11140-5, exposes air leaks and vacuum pump faults before they can compromise a load. CliniEco Medical carries the CliniEco Medical Bowie-Dick Test Pack — ISO 11140-5 Type 2, Daily Vacuum Check, 6-Pack for clinics that run it daily.
Quick facts: A B-D test is a daily air-removal challenge for pre-vacuum sterilizers, run before the first load in an empty chamber. The sheet is an ISO 11140-5 Type 2 indicator, and cycles commonly run about 3.5 minutes at 134 °C. A uniform color change passes; a lighter centre means air remained and the sterilizer should not be used. A B-D test does not replace biological monitoring.
Why air leaks are invisible until it is too late
Pre-vacuum sterilizers pull air from the chamber and wrapped loads before steam enters. Air insulates, blocks steam contact, and keeps surfaces below the temperature needed to kill microorganisms. A slow air leak or weakening vacuum pump can leave air pockets behind even when the machine finishes a normal-looking cycle.
None of this shows from the outside: loads look dry and displays read complete, yet instruments were never fully exposed to steam. The Bowie-Dick test makes that failure visible before the first load of the day.
What a Bowie-Dick test measures
A B-D pack holds a paper sheet printed with chemical indicator ink. Run through a dedicated cycle in an empty chamber, it forces steam to penetrate evenly. Working air removal turns the whole sheet uniformly dark; remaining air collects near the centre and leaves a lighter patch.
The lighter centre is the design at work — air traps mid-pack, where the sheet reveals it. The test does not prove sterilization; it proves air removal happened first.
ISO 11140-5 Type 2: the standard behind the pack
Bowie-Dick test sheets are ISO 11140-5 Type 2 indicators: built for a specific procedure, the air-removal challenge for pre-vacuum sterilizers, not for routine load monitoring. The CliniEco Medical pack follows this design and ships as a 6-pack — a daily run plus spares for retests after service.
| Tool | Checks | Typical frequency | Answers |
|---|---|---|---|
| Bowie-Dick pack (ISO 11140-5 Type 2) | Air removal in an empty chamber | Daily, before the first load | Did air leave the chamber? |
| Biological indicator | Spore killing under steam | Each day the sterilizer is used in Ontario (RCDSO) | Did sterilization happen? |
| Class 5 integrator, per pack | Steam, time, temperature in one pack | With every pack processed | Was this pack exposed correctly? |
Running the test: placement, cycle, reading
- Start with an empty chamber warmed to working temperature.
- Place the pack flat over the drain point at the front bottom of the chamber.
- Run the dedicated B-D program — about 3.5 minutes at 134 °C; follow the manufacturer's instructions.
- Open the pack and read the sheet under normal lighting.
A uniform dark color change passes; a lighter centre patch fails. Many sterilizers offer an automatic B-D program that sets the time and temperature.
Pass, fail and what to do next
On a pass, record the result and run the day's loads as usual. On a fail, do not use the sterilizer: tag it out of service and call your service provider. After repair, run a fresh B-D test — the sterilizer returns to service only when the sheet is uniform. Keep a dated log for inspections.
Bowie-Dick vs the rest of your monitoring
The B-D test asks one question: did air leave the chamber? Biological indicators ask the second — were spores killed? — and Ontario's RCDSO requires them on each day the sterilizer is used — daily, not weekly. Some public health guidance encourages daily testing as a stronger routine, but the weekly CDC / AAMI ST79 cadence is the U.S. baseline.
Class 5 integrators cover the third layer: steam, time and temperature inside each pack. A solid routine pairs a daily B-D pack with a weekly CliniEco Medical Biological Indicator — 24h Rapid Readout, 25-Pack and a CliniEco Medical Steam Chemical Integrator — Class 5, ISO 11140-1 Type 5, 100-Pack in every pack, so each layer is checked.
FAQ
How often do I run a Bowie-Dick test?
Once a day, before the first load, in an empty chamber. Daily B-D testing is standard practice for pre-vacuum sterilizers under manufacturer and CSA guidance — a failure is cheaper to catch in an empty chamber than in a full load.
What does a failed Bowie-Dick test mean?
It means the sterilizer did not remove air completely — usually an air leak, faulty vacuum pump or blocked drain. Keep the sterilizer out of service until it is repaired and a fresh B-D test passes.
Can a Bowie-Dick test replace a biological indicator?
No. The B-D test checks air removal; a biological indicator checks whether spores were killed. Ontario's RCDSO requires biological monitoring on each day the sterilizer is used, so the two work as a pair.
What temperature is a Bowie-Dick cycle?
About 134 °C for roughly 3.5 minutes. Exact time and temperature follow the sterilizer and pack manufacturer's instructions, so check the label first.
Where do I place the test pack in the chamber?
Flat, in an empty chamber, over the drain point — usually the front bottom tray. Residual air collects there, making it the position most likely to catch a real leak.
Related reading: see the full dental compliance hub for RCDSO-ready checklists.
see our RCDSO spore-testing pillar article for the daily BI requirement.
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