A process challenge device, or PCD, is a test package designed to be harder to sterilize than the routine load, so that if the PCD passes, the ordinary instruments around it passed too. Think of it as a worst-case stand-in: the device deliberately restricts steam penetration or air removal, forcing the sterilizer to prove itself under the least favourable conditions you are likely to see. This explainer covers what a PCD is, how it differs from an ordinary indicator, and when Canadian clinics should use one.
What is a process challenge device?
A PCD is a defined combination of a sterilizing-agent challenge and a monitoring indicator, assembled so that it presents a greater obstacle than the items in a normal load. The challenge could be a narrow lumen, a wrapped tray, or a specific holder that slows steam access. The indicator inside, either a chemical indicator or a biological indicator, tells you whether the challenge was overcome. The key idea is that a PCD tests the process, not just a spot on a pouch.
What is the difference between a PCD and an ordinary indicator?
An ordinary chemical indicator sits on or in a pack and responds to the conditions at that point. A PCD is engineered to be the hardest point, so a pass carries more weight. That is why a Class 5 integrator used inside a validated PCD gives a stronger signal than an external indicator tape, which only shows the pack was exposed. If your quality system relies on external tape alone, you are checking exposure, not lethality or penetration.
Is a Bowie-Dick test a PCD?
Yes. The Bowie-Dick test is a recognised PCD for air removal in pre-vacuum sterilizers, and it is specified as a Class 2 indicator under ISO 11140-5. It is run on an empty chamber at the start of the day to confirm that air is being removed properly before any load goes in. A failed or unclear Bowie-Dick sheet means the sterilizer should not be used for patient loads until the fault is corrected.
How often should a PCD be used?
| Test | Standard | What it verifies | Typical cadence |
|---|---|---|---|
| Bowie-Dick test pack | ISO 11140-5, Class 2 | Air removal in pre-vacuum sterilizers | Start of each operating day |
| Class 5 chemical integrator | ISO 11140-1, Type 5 | All critical cycle parameters in one readout | Every load, per policy |
| Biological indicator in a PCD | Matched to the cycle type | Lethality under a worst-case challenge | Every day the sterilizer is used in Ontario |
Does a PCD replace a biological indicator?
No. They answer different questions. A chemical PCD shows that conditions were delivered to a hard-to-reach point; a biological indicator shows the cycle actually killed spores. In Ontario, the RCDSO expects a biological indicator on every day the sterilizer is used - daily monitoring, not weekly. The weekly baseline is the CDC / AAMI ST79 standard in most US states. Use both: a PCD as your process challenge and a daily biological indicator as your lethality check.
Which PCD products fit a clinic?
For pre-vacuum sterilizers, a daily Bowie-Dick test pack, ISO 11140-5 Type 2 covers air removal, and a Class 5 steam chemical integrator, ISO 11140-1 Type 5 covers load-level process control. Pair them with a daily biological indicator, and the two together give you the evidence trail an inspector or college reviewer will ask for.
Clinics that want the paperwork side handled for them can print the printable sterilization log, run the sterilization self-check, or talk to a sterilization compliance specialist. Buying for a multi-site group? Wholesale ordering covers case and pallet volumes, and the BI 5-pack trial (CA $12.99, shipping included) is the low-commitment way to test monitoring consumables first. Reselling? become a distributor.
Where to Buy Biological Indicators in Canada
CliniEco Medical supplies these from Ontario with published CAD pricing (MDEL #35334) — no quote required, and each pack ships with the lot number printed on it so your monitoring record stays traceable.
| Format | Pack size | Price (CAD) | |
|---|---|---|---|
| 24-hour self-contained | 25-pack | $84.99 | Order |
| 24-hour self-contained | 100-pack | $299.00 | Order |
| 3-hour rapid fluorescence | 50-pack | $274.99 | Order |
Which format does your sterilizer actually need?
Match the readout time to how fast you need the result: a 24-hour self-contained indicator works in any gravity or pre-vacuum cycle with a standard incubator, while a 3-hour fluorescence tube needs the matching reader. Running one cycle type per day, the 25-pack covers a month; busier clinics move to the 100-pack and cut the per-test cost.
How much do spore tests cost in Canada?
Published pricing runs $3.40 per test on the 25-pack down to $2.99 on the 100-pack — no distributor quote, no account needed.
Not sure which format your sterilizer needs? Generate a free sterilization log sheet first — it maps your cycles and tells you the pack size that fits. Questions about your setup? Ask a Compliance Specialist.
Related Reading
- Sterilization compliance hub
- 20-minute biological indicators in Canadian sterilization practice
- Autoclave pouch workflow: material, indicator, seal and storage decisions
- Bowie-Dick test packs, Type 2
Frequently Asked Questions
What is a process challenge device in sterilization?
A PCD is a test package built to be harder to sterilize than a normal load, so a pass shows the process overcame a worst-case challenge rather than an easy spot.
Is a Bowie-Dick test a process challenge device?
Yes. The Bowie-Dick test is a recognised PCD for air removal in pre-vacuum sterilizers and is specified as a Class 2 indicator under ISO 11140-5.
Does a PCD replace daily biological indicator testing?
No. A PCD shows conditions reached a hard-to-reach point, while a biological indicator proves lethality, and Ontario clinics are expected to run a biological indicator every day the unit is used.
Which chemical indicator class belongs inside a PCD?
Class 5 integrators under ISO 11140-1 are commonly used inside PCDs because they respond to all critical cycle parameters in a single readout.
Last updated: October 2026. CliniEco Medical is a licensed medical device establishment (MDEL #35334).
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