Quick facts
- ISO 17665:2024 is the international standard for moist heat sterilization of medical devices. It consolidated ISO 17665-1:2006, ISO/TS 17665-2:2009 and ISO/TS 17665-3:2013 into one document, so a procedure manual that still cites a 17665 sub-part is quoting identifiers that are no longer current.
- Clause 1 states that the document covers the development, validation and routine control of moist heat processes and that the application in industrial and health care settings is considered. Annex F is guidance for health care facilities; Annex H is the industrial counterpart.
- The standard sets no monitoring frequency. In Ontario the frequency comes from elsewhere: one biological indicator in a process challenge device, each day the sterilizer is used and for each type of cycle used that day.
- Every clause from 1 to 12 is mapped below against what a Canadian dental or medical clinic already does, together with the seven normative references of Clause 2 and the cadence the standard deliberately leaves open.
Three documents govern a sterilizer in a Canadian clinic, and they do not overlap. One defines what a validated moist heat process is. One fixes how often the process has to be monitored and what has to be written down. One sets the authority behind the first two. ISO 17665:2024 is the first of the three, and it is the one clinic teams read least often, because it is written in the language of process validation rather than the language of a bench in a treatment room.
Read clause by clause, though, it answers questions that clinic teams argue about: what counts as a validated cycle, who signs off on validation, when a sterilizer has to be requalified, what the release decision rests on, and how long a record has to survive. This article reads the clause list against Canadian clinic practice and marks the places where a routine has quietly drifted from the requirement.
What does ISO 17665:2024 cover, and where does a Canadian clinic sit inside it?
ISO 17665:2024, Sterilization of health care products — Moist heat — Requirements for the development, validation and routine control of a sterilization process for medical devices, is published by ISO technical committee TC 198 — the same committee behind the biological indicator and chemical indicator standards a clinic already buys against. The standard is not written only for factories. Its own definitions in Clause 3 include "health care facility", and the examples given there name hospitals, free-standing ambulatory surgical centres, nursing homes, extended care facilities and "medical, dental and physician offices or clinics". Clause 1 then says plainly that the application in industrial and health care settings is considered, which is why the annex structure runs to eight annexes: four of general guidance, one on cycle examples, one on saturated steam properties, one for health care facilities and one for industrial settings.
For a clinic, the practical consequence is that the normative clauses — the ones conformance is claimed against — apply to the bench sterilizer in the reprocessing room just as they apply to a chamber on a factory floor. What changes between the two settings is the scale of documentation and who performs which activity, not whether the requirements exist. The informative annexes are explicit that they are guidance for a uniform understanding of the requirements, not a checklist for assessing conformance — a point worth remembering the next time a supplier presents an annex table as if it were the requirement itself.
Which process types does Clause 1.1 bring into scope, and does your sterilizer match one?
Clause 1.1 lists the moist heat processes the standard covers. They are saturated steam sterilization in which air is removed by passive purging, which is the gravity displacement principle; saturated steam sterilization in which air is removed by active air removal, described in the standard as dynamic air removal or pre-vacuum and fractionated vacuum; and three contained product processes, where heat transfer is achieved by steam or steam-air mixtures, by water sprays, or by water immersion.
Clause 1.2 sets the boundary. The standard does not specify requirements for inactivating the causative agents of spongiform encephalopathies such as scrapie, bovine spongiform encephalopathy and Creutzfeldt-Jakob disease, and it points to the ISO 22442 series for that subject. It does not apply to processes built on a combination of moist heat with another sterilizing agent. It does not set requirements for occupational safety in the design and operation of sterilization facilities.
The distinction that clinics most often miss is between a saturated steam load and a contained product. In a saturated steam process, saturated steam contacts every surface to be sterilized. In contained product sterilization, the chamber environment is used for heating and cooling only; the sterilizing effect is created inside the sealed item, such as a solution in a bottle. The load definition, the challenge device and the monitoring logic differ between the two, and the standard treats them as separate process families in Clause 6.3 and Clause 6.4 respectively. A clinic that runs a wrapped-instrument cycle on Monday and sterilizes a sealed container on Friday is running two processes under one label.
How does every clause read against a Canadian clinic bench?
Table 1 maps the normative clauses to what a clinic already does, and to where the routine and the requirement have come apart.
| Clause | What ISO 17665:2024 requires there | What it looks like on a Canadian clinic bench | Where clinics commonly fall short |
|---|---|---|---|
| 1 Scope (1.1 inclusions, 1.2 exclusions) | Covers gravity displacement, dynamic air removal and three contained product processes; excludes TSE agents, combined processes and occupational safety | Bench steam sterilizer running gravity or pre-vacuum cycles; sealed liquid loads sit under contained product | Treating every cycle as "the autoclave" with no distinction between saturated steam and contained product loads |
| 2 Normative references | Biological indicators (ISO 11138-1, ISO 11138-3), chemical indicators (ISO 11140, all parts), packaging (ISO 11607-1 and ISO 11607-2), bioburden (ISO 11737-1 and ISO 11737-2) | The indicator, tape and pouch on the reprocessing shelf | External tape only, no internal indicator, and packaging that was never validated for forming and sealing |
| 3 Terms and definitions | Equilibration time, holding time, Fo value, D value, FBIO value, health care facility | The gap between total cycle time and the period held within the sterilization temperature band | Logging only the total cycle time printed on the display |
| 4 General | Documented process controls: control of documentation, management responsibility, resources, control of externally provided product, identification and traceability, control of non-conforming product | A written reprocessing protocol, trained staff, signed records | The protocol exists as habit rather than as a controlled document |
| 5 Sterilizing agent characterization (5.1 to 5.4) | Agent characterization, microbicidal effectiveness, effects on materials, environmental consideration | The steam and the water that feed the chamber | Untreated water feed, boiler additives, no water-quality record |
| 6 Process and equipment characterization (6.1 to 6.5) | Process characterization; saturated steam processes (6.3) and contained product processes (6.4); equipment (6.5) | Cycle variables, air removal, chamber, door seal | No air-removal test evidence on dynamic air removal sterilizers, and no written cycle-parameter specification |
| 7 Product definition | Device families, configurations and the worst case presented for processing | Which instruments go into which load, in which packaging configuration | Loads assembled by convenience, with no defined family or worst case |
| 8 Process definition | Specified cycle parameters for the defined product | Selecting the cycle for the load in hand | One cycle used for every load |
| 9 Validation (9.1 to 9.5) | Installation qualification (9.2), operational qualification (9.3), performance qualification (9.4), review and approval of validation (9.5) | Vendor installation documentation at commissioning; requalification after a major repair | No performance qualification record, and no requalification after repair or relocation |
| 10 Routine monitoring and control (10.1 to 10.6) | Routine monitoring (10.1), operational status (10.2), process verification (10.3), added data for saturated steam (10.4) and contained product (10.5), record retention (10.6) | Daily biological indicator, chemical indicators, physical parameters, log book | Cycle-type coverage, and record retention |
| 11 Product release from sterilization | A release procedure that is defined and recorded | Routine loads released on an internal indicator plus physical parameters; implant loads held until the biological indicator is read | Implantable devices released before the indicator result is known |
| 12 Maintaining process effectiveness (12.1 to 12.6) | Recalibration (12.3), equipment maintenance (12.4), requalification (12.5), assessment of change (12.6) | Instrument recalibration, documented maintenance, requalification after a major repair | The change assessment that is never written: new door gasket, software update, change in the steam or water supply |
Two clause groups deserve more than a table cell.
Clause 9 splits validation into installation qualification, operational qualification and performance qualification, then closes with review and approval of validation at 9.5. In a clinic the first two usually arrive as vendor documentation at commissioning, and the third is the one with no paper trail. Performance qualification is the record that the process, under anticipated conditions, consistently produces a product meeting all predetermined requirements — which in clinic terms means evidence from the clinic's own loads, in the clinic's own packaging configurations, on a full test load, not an empty chamber only.
Clause 12.6, assessment of change, is the clause with the thinnest paper in most offices. A replaced door gasket, a sterilizer software update, a switch in the water treatment system or a change in steam supply are all changes that can move process performance, and the standard requires that their effect be assessed. AAMI's definition of a major repair in ANSI/AAMI ST79 handles the extreme case — a repair outside the scope of routine preventive maintenance that significantly affects equipment performance, with examples such as a software upgrade or the replacement of the water pump, detergent delivery, heating, water delivery, water treatment or ultrasonic generator system or computer controls — but the change assessment clause is broader than any repair list. It is the requirement to notice change at all.
Which normative references in Clause 2 decide what you buy?
Clause 2 names seven documents, and every one of them lands on a consumable, a record or a validation activity in the reprocessing room.
| Clause 2 reference | What the document governs | Where it shows up in a clinic |
|---|---|---|
| ISO 11138-1:2017 | General requirements for biological indicators | Which indicator products meet the baseline requirement at all |
| ISO 11138-3:2017 | Biological indicators for moist heat sterilization processes | The spore test used on the daily cadence |
| ISO 11140 (all parts) | Chemical indicators, including the class system | External tape and the internal indicator in every pack |
| ISO 11607-1 | Materials, sterile barrier systems and packaging systems | The pouch, reel or wrap a pack is built from |
| ISO 11607-2 | Validation requirements for forming, sealing and assembly processes | The heat sealer and its seal validation |
| ISO 11737-1 | Determining a population of microorganisms on products | The bioburden assumption behind the cleaning step |
| ISO 11737-2 | Tests of sterility in defining, validating and maintaining a process | Process validation, as distinct from routine monitoring |
Two of these are undated references in the Clause 2 list, which means the current edition applies rather than a fixed year. The introduction to the standard adds two more pointers that matter in a clinic: ISO 15883 for automated cleaning and disinfection, and ISO 17664-1 for the instructions a device manufacturer has to supply for reprocessing. Those two sit upstream of moist heat sterilization — nothing in ISO 17665:2024 will rescue a load that was not cleaned to the standard the sterilizer is entitled to assume.
What does the standard not set, and who sets it in Ontario?
Clause 10 requires routine monitoring, a defined operational status, process verification against the validated process, evaluation of additional data, and record retention. It does not name a cadence, an indicator format or a number of years. That is deliberate: a frequency is a regulatory decision, not a process-validation decision. In Ontario the cadence is set by the college and restated in provincial guidance, and both say the same thing.
| Source | Cadence it states | What it covers |
|---|---|---|
| RCDSO, Standard of Practice: Infection Prevention and Control, v3, p.24 | Each day the sterilizer is used and for each type of cycle used that day | Biological indicator in a process challenge device, with a control test; p.25 sets the log at a minimum of ten years from the last entry |
| Provincial PIDAC guidance, cleaning, disinfection and sterilization, 3rd edition, p.41 | The same daily wording, per sterilizer and per cycle type | Biological monitoring; p.40 adds a daily air removal test on dynamic air removal sterilizers |
| CDC, Guideline for Disinfection and Sterilization in Healthcare Facilities, 2008, p.77 | At least weekly, with daily described as allowing earlier discovery of malfunction or operator error | The United States baseline; it is not the Ontario requirement |
| ANSI/AAMI ST79:2017/(R)2022, 13.5.3.2 | At least weekly, preferably every day the sterilizer is in use | The United States consensus standard, including qualification testing after a major repair |
| ISO 17665:2024, Clause 10 | No cadence: routine monitoring, process verification and records against the validated process | The mechanics a clinic has to satisfy whatever the frequency is |
The weekly figure that circulates in purchasing conversations is the American baseline. Where a clinic's written protocol borrows it and presents it as what Ontario expects, the protocol is wrong on its face, and the arithmetic is not subtle: a five-day clinical week monitored weekly produces 52 monitoring events a year, while the daily rule with a single cycle type produces roughly 260.
Which annexes does a clinic actually use?
The eight annexes are not equal in value to a clinic. Annex A sets out the principles of moist heat sterilization and the rationales behind the requirements. Annex B and Annex C describe two different ways to establish a process — primarily from microbiological inactivation, or primarily from measurement of physical parameters. Annex D gives examples of moist heat sterilization cycles. Annex E tabulates the temperature and pressure of saturated steam.
Annex F is the one to read first: guidance on applying the normative requirements in health care facilities. Annex G is the one to read second: guidance on designating a medical device to a product family and processing category, which is the standard's answer to "may these different instruments share a load". Annex H is the industrial counterpart to Annex F and becomes relevant when a clinic compares its own paperwork against what a contract sterilizer produces.
The standard's own note on its guidance is worth keeping: the informative annexes are not intended as checklists for assessing conformance. Methods other than those in the guidance may be used if they achieve conformance with the requirements. A supplier who hands you an annex table and calls it the standard has handed you a starting point, not the requirement.
How should the record look so both regimes are satisfied?
The record that satisfies a college practice review is built from fields that are already defined for the province: date, sterilizer number, load number, load contents, cycle, sterilization time, temperature, pressure and the name of the person responsible, then the package-label line, then the service and maintenance entries and the malfunction entries. Add the three result types the logbook has to carry — physical, chemical and biological — and the retention rule, which is where the standard's Clause 10.6 and the college's ten-year minimum meet.
For a closer reading of how those fields fit a single page, see the fourteen-field record layout in an audit-ready autoclave log.
Where the requirement and the routine meet
For a clinic that wants the process side and the consumable side in one place, the working set is small: a 24-hour self-contained biological indicator 25-pack for the daily cadence and its control, a fifteen-well dry-block incubator so a full day of indicators can run together, sterilization indicator tape for the external indication on every pack, and a five-pack indicator trial if you want to price the cadence before committing a year to it. The sterilization compliance hub indexes the requirements these articles quote, the sterilization monitoring collection gathers the monitoring lines in one shelf, and clinics buying for more than one location can open a wholesale account and buy the cadence at case quantities.
Related reading
The frequency rules, province by province, including the Ontario daily requirement and the repair-triggered testing rules, are set out in spore test frequency after a major sterilizer repair and in daily practice; the three sterilizing modalities and the standards behind them are compared in ISO 17665, ISO 11135 and ISO 11137 side by side; for the generic standard that applies when a process has no dedicated document, see ISO 14937 and sterilizing agent characterization; for what happens inside the chamber, see the phases of a steam sterilization cycle; for the one class of contamination the standard excludes, see what Canadian guidelines say about prions and autoclaves; and for the Ontario and United States split in writing, see CSA Z314 versus CDC sterilization rules in Canada and the United States. and for the standard that governs liquid chemical sterilants and animal-tissue devices at the manufacturing stage, see ISO 14160:2020 and what it actually requires.
Frequently Asked Questions
Does ISO 17665:2024 replace ISO 17665-1?
Yes. The 2024 edition consolidated the three previous documents — ISO 17665-1:2006, ISO/TS 17665-2:2009 and ISO/TS 17665-3:2013 — into a single standard covering requirements and guidance together. Procedure manuals, supplier declarations and technical files that still cite a 17665 sub-part are referring to withdrawn identifiers, and a document review that asks a supplier which edition is cited will surface the gap quickly.
Does ISO 17665:2024 tell me how often to run a biological indicator?
No. Clause 10 requires routine monitoring, process verification against the validated process and records, but it does not set a frequency, an indicator format or a retention period. In Ontario the frequency comes from the college standard and provincial guidance: one biological indicator in a process challenge device on each day the sterilizer is used, and for each type of cycle used that day, with a control test.
Is a weekly spore test enough for a sterilizer in Ontario?
Weekly is the CDC and AAMI ST79 baseline in United States facilities. It is not the Ontario requirement, where the cadence is tied to each day of use and each cycle type. A clinic that is running a weekly routine and believes it is meeting the college standard is under-monitoring on paper and in practice, and the gap widens with every additional cycle type it operates.
When does a sterilizer have to be requalified?
Clause 12.5 requires requalification to confirm that a process remains acceptable, and Clause 9 defines the validation it repeats. In Canadian practice the trigger list is well documented: installation, relocation, major repair, unexplained sterility failures, and changes in the steam supply. Provincial guidance treats a sterilizer with a positive result on any requalification test as not approved for use until it passes.
What is the difference between equilibration time and holding time?
Equilibration time is the period between the reference measurement point reaching the defined process parameters and every point in the load reaching them; it is also called sterilization time lag. Holding time is the period during which the reference point and all points in the load are continuously within the sterilization temperature band. A clinic that records only the total cycle time from the display has recorded neither, which is why Clause 10.6 requires records to show the process variables rather than the cycle duration alone.
Does ISO 17665:2024 cover prion inactivation?
No. Clause 1.2.1 excludes the causative agents of spongiform encephalopathies, including Creutzfeldt-Jakob disease, and points to the ISO 22442 series instead. A clinic handling instruments that may carry prion contamination is working outside the moist heat standard's scope, and the relevant provincial guidance governs what happens next.
CliniEco Medical holds MDEL #35334.
Sources
- ISO 17665:2024 — Sterilization of health care products — Moist heat — free preview showing the scope, clause list, annexes and terms (PDF)
- iTeh Standards catalogue record for ISO 17665:2024, including the reference to ISO/TC 198
- ISO 14937:2009 — General requirements for characterization of a sterilizing agent — free preview (PDF)
- ISO 17664-1:2021 — Information to be provided by the medical device manufacturer for processing — free preview (PDF)
- ISO 15883-1:2024 — Washer-disinfectors, general requirements — free preview (PDF)
- ANSI/AAMI/ISO 11138-3:2017 — Biological indicators for moist heat sterilization processes, preview (PDF)
- ISO 11135:2014 with Amendment 1:2018 — Ethylene oxide sterilization, catalogue record
- RCDSO — Standard of Practice: Infection Prevention and Control, v3 (PDF)
- Public Health Ontario / PIDAC — provincial guidance for cleaning, disinfection and sterilization in all health care settings, 3rd edition (PDF)
- CDC — Guideline for Disinfection and Sterilization in Healthcare Facilities, 2008
- ANSI/AAMI — ST79, comprehensive guide to steam sterilization and sterility assurance
- CSA Group — CAN/CSA-Z314, medical device reprocessing in all health care settings
- CliniEco Medical — sterilization compliance hub
- CliniEco Medical — 24-hour self-contained biological indicator, 25-pack
- CliniEco Medical — five-pack biological indicator trial
- CliniEco Medical — spore test frequency after a major repair and in daily practice
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