A Type 5 indicator and a Type 6 indicator are both internal chemical indicators, and they are not interchangeable. Type 5 - an integrating indicator - reacts to all critical variables in the cycle and has stated values that correlate to a biological indicator at three time and temperature relationships; Type 6, an emulating indicator, responds to all critical variables for one specified cycle, so a different Type 6 is needed for every cycle time and temperature in use. The naming causes avoidable confusion too: "Type 5" and "Class 5" are the same object under two naming systems, and the same is true of Type 6 and Class 6.
Quick facts
- EN ISO 11140-1:2014 is where the "Type" numbering comes from; North American training material and many procedure manuals say "Class" for the same six categories. Type 1 through Type 6 map one-to-one onto Class 1 through Class 6.
- Type 5 is the only chemical indicator class with a defined requirement to correlate to a biological indicator, at three stated time and temperature relationships.
- A Type 6 indicator is cycle-specific. Public Health Ontario's guidance states that a different Class 6 emulating indicator is required for each sterilization cycle time and temperature used, so a clinic running two cycle types stocks two Type 6 SKUs.
- Neither type replaces the biological indicator. Ontario requires a biological indicator for each sterilizer on every day it is used; no chemical indicator class discharges that duty.
- ISO 11140-6:2022 covers a different object - Type 2 indicators and process challenge devices for performance testing of small steam sterilizers conforming to EN 13060.
What is the difference between a Type 5 and a Type 6 indicator
The dividing line is the scope of the cycle the indicator represents.
A Type 5 integrating indicator reacts to all critical variables - time, temperature and the presence of steam - and carries stated values that correlate to a biological indicator at three time and temperature relationships. That correlation is why Type 5 indicators appear in load-release discussions: the indicator reports a measured response tied to spore lethality at more than one point on the cycle curve.
A Type 6 emulating indicator also reacts to all critical variables, but only for a specified cycle - a 10-minute, 18-minute or 40-minute cycle at a stated temperature, for example. Because the response is tied to that single cycle, a clinic running a 134 C vacuum-assisted cycle and a longer gravity cycle needs a Type 6 matched to each.
| Type | What it reacts to | What it can do | What it cannot do |
|---|---|---|---|
| Type 1 | Exposure to the process | Differentiate processed from unprocessed items; external package labelling | Say anything about adequacy of the cycle |
| Type 2 | Specific test procedures such as air removal or steam penetration | Support equipment tests such as the Bowie-Dick style air removal test | Monitor routine loads as a pack-level indicator |
| Type 3 | A single critical variable | Report one parameter, for example achieved temperature | Represent the cycle as a whole |
| Type 4 | Two or more critical variables | Internal pack monitoring against manufacturer-specified conditions | Claim correlation to a biological indicator |
| Type 5 | All critical variables, with correlation to a biological indicator at three time and temperature relationships | Internal pack monitoring; may be used as an additional tool to release routine loads that do not contain implants | Replace the biological indicator |
| Type 6 | All critical variables for one specified cycle | Internal pack monitoring for that cycle only | Cover a different cycle time or temperature; release routine loads on the same basis as Type 5 |
Why do some documents say Type 5 and others say Class 5
Both are correct; they are two naming systems for one set of categories. The international standard numbers the indicators as Types 1 to 6, and North American operating procedures, in-house policies and supplier catalogues commonly use Class 1 to Class 6. The North American convention predates the current edition of the international standard and survived the alignment.
The practical consequence is in documentation. A procedure that says "Class 5 or better in every pouch" and a supplier quotation that says "Type 5 integrator" describe the same requirement, but an auditor reading both has no way to know that unless the clinic says so. Write the pairing into the policy - one line naming EN ISO 11140-1, the type number and the equivalent class number - and the ambiguity disappears. It also prevents stocking a Type 4 strip in the belief that it is a Type 5 integrator.
ISO 11140-1:2014 is the third edition of the general requirements standard and the edition that defines the six types.
Can a Type 5 or Type 6 indicator replace the biological indicator
No. Public Health Ontario's guidance is direct: chemical indicators do not replace the need to use a biological indicator, and they do not indicate that a device is sterile - only that the package has been processed through a sterilization cycle. The Ontario requirement runs alongside it: a biological indicator must be used for each sterilizer on every day the sterilizer is used, with a control test recorded at the same time.
There is one place where the distinction matters operationally rather than academically. Where items cannot be quarantined until the biological indicator result is known, Public Health Ontario's guidance permits evaluation of a Class 5 or Class 6 chemical indicator together with the specific cycle physical parameters to justify releasing routine loads. That permission is about release timing, not about monitoring. It does not remove the biological indicator from the day, and it does not apply to implantable devices, which are to be quarantined until the biological indicator result is available.
A technical note from the biological indicator side of the market makes the same point: a Class 5 integrating indicator is the only chemical indicator with defined requirements for correlation to a biological indicator under the indicator standards. That is a statement about what Type 5 does, not a licence to stop testing.
| Dimension | Type 5 integrating indicator | Type 6 emulating indicator |
|---|---|---|
| Response basis | All critical variables, correlated to a biological indicator at three time and temperature relationships | All critical variables, for one specified cycle |
| Cycle coverage | A range of cycles within the stated values | One cycle time and temperature |
| Load release for routine, non-implant loads | Named in Public Health Ontario guidance as usable, with the cycle physical parameters, when quarantine is not possible | Public Health Ontario's class table states it cannot be used to release loads that do not contain implants |
| Implant loads | Not a release basis; quarantine until the biological indicator result is known | Not a release basis |
| SKUs needed for two cycle types | One family, if the stated values cover both cycles | Two, one per cycle time and temperature |
| Placement | Inside the package or tray, in the area judged least accessible to steam | Inside the package or tray, per manufacturer instructions for that cycle |
| Documentation burden | One policy line stating the correlation basis | Cycle time and temperature must be matched to the product on every order |
| Replaces the daily biological indicator | No | No |
How many indicator SKUs does each choice create
This is where the class system starts costing shelf space. A clinic with two sterilizers running the same 134 C vacuum-assisted cycle is unaffected. A clinic running a flash cycle for unbagged items, a 134 C wrapped cycle and a longer gravity cycle needs three matched Type 6 products, and every substitution check at restocking time becomes a cycle-matching exercise. A Type 5 with stated values covering the clinic's cycle range is one product line for the same workload; the trade is that staff read a stated value against a stated cycle instead of seeing a pass mark tied to one cycle. What is not legitimate is ordering Type 6 for one cycle and using it in another.
The volumes add up quickly. A clinic monitoring daily under the Ontario position consumes roughly 250 biological indicators per sterilizer per year, one internal indicator per package, and one air removal test each day the sterilizer is used. The Class 4 dual-indicator sterilization pouch carries external and internal indicators on the pouch itself, the daily vacuum check test pack covers the Type 2 air removal test, and a biological indicator 5-pack trial is the smallest way to sample the daily monitoring workflow before setting a standing order; the 50-pack 24-hour self-contained box is the more usual monthly line for a single sterilizer.
Does ISO 11140-6 change what I buy
ISO 11140-6:2022 covers Type 2 indicators and process challenge devices for performance testing of small steam sterilizers conforming to EN 13060. It addresses equipment performance testing, not pack-level internal monitoring, so it does not change what goes inside a package. The boundary is worth stating in a policy: a Type 2 air removal device tests whether the sterilizer removed air from the chamber and load, while a Type 5 or Type 6 inside a package reports what happened in that package.
What the Ontario rules require alongside the indicators
Three requirements run in parallel: an external Type 1 indicator on every package to distinguish processed from unprocessed items; an internal chemical indicator in every package, container or bundle, placed in the area judged least accessible to steam penetration, with the class chosen according to the parameters being measured and the precision needed; and a biological indicator for each sterilizer on every day it is used, with a control test. For dynamic air removal sterilizers, an air removal test is performed at the beginning of each day the sterilizer is used. Public Health Ontario's guidance also ties the biological indicator to each type of cycle used that day.
Where a clinic's written policy allows a Class 6 indicator to justify releasing routine loads, that line is worth re-reading against the source documents. Public Health Ontario's policy sentences and its class table do not read identically on the point, and the conservative practice - a Type 5 with the cycle physical parameters where release without quarantine is unavoidable, and quarantine for implant loads regardless - survives an audit without an argument.
Sources
- ISO 11140-1:2014, Chemical indicators - Part 1: General requirements, third edition (sample document) - checked 16 September 2026
- STERIS technical library, 6 ISO types of chemical indicators - checked 16 September 2026
- Solventum (3M) technical note, Class 6 emulating indicators - checked 16 September 2026
- ISO 11140-6:2022, Type 2 indicators and PCDs for small steam sterilizers - checked 16 September 2026
- EN ISO 11140-1:2014 catalogue entry - checked 16 September 2026
- ISO 11140-4:2007, Class 2 indicators as an alternative to the Bowie and Dick test - checked 16 September 2026
- Public Health Ontario PIDAC cleaning, disinfection and sterilization guidance, 3rd edition, 2013 - checked 16 September 2026
- RCDSO, infection prevention and control in the dental office: some common issues - checked 16 September 2026
- RCDSO standards, guidelines and advisories on infection prevention and control - checked 16 September 2026
- ISO 11139:2018, sterilization vocabulary - checked 16 September 2026
- ANSI/AAMI/ISO 11138-7:2019, selection, use and interpretation of biological indicator results - checked 16 September 2026
- ANSI/AAMI/ISO 11138-1:2017, biological indicators - general requirements - checked 16 September 2026
- EN ISO 11138-3:2017, biological indicators for moist heat sterilization - checked 16 September 2026
- Kunyk et al., Daily Use of Biologic Indicators in General Dental Practice, J Can Dent Assoc 2021;87:l11 - checked 16 September 2026
- Vatanparast et al., biological indicator failure rates in Saskatchewan dental practices, BMC Oral Health 2024 - checked 16 September 2026
- ISO 17665:2024, moist heat sterilization requirements - checked 16 September 2026
Ordering for a clinic, lab or care home? Wholesale and multi-site ordering covers case pricing and account setup, and the B2B wholesale collection lists the lines stocked for institutional buyers.
Related reading
The six-category system is set out class by class in our ISO 11140-1 explained guide to chemical indicator classes, and the buying decision across all six is covered in the ISO 11140-1 classes buying guide. For what happens when the indicator does not pass, see the case review a Class 5 integrator was rejected - how one clinic responded, and the wider three-layer monitoring picture sits in our sterilization compliance hub.
Related Reading
- ISO 11140-1 explained guide to chemical indicator classes
- ISO 11140-1 classes buying guide
- A Class 5 integrator was rejected - how one clinic responded
- Sterilization compliance hub
- dental clinic sterilization supplies
- free Ontario sterilization compliance log
Frequently Asked Questions
Is Type 5 the same as Class 5
Yes. Type 5 and Class 5 name the same indicator - an integrating indicator that responds to all critical variables and has stated values correlating to a biological indicator at three time and temperature relationships. The same applies to Type 6 and Class 6. The international standard uses Type numbering while North American procedure manuals and catalogues commonly use Class numbering.
Can I use a Type 6 indicator instead of a biological indicator
No. A chemical indicator does not replace the biological indicator, and Public Health Ontario's guidance states that chemical indicators do not indicate that a device is sterile - only that the package went through a sterilization cycle. Ontario requires a biological indicator for each sterilizer on every day it is used, with a control test recorded alongside.
Why does a Type 6 indicator only work in one cycle
Because its response is built for one specified cycle time and temperature, for example a 10-minute or 18-minute cycle. Public Health Ontario's class table states that a different Class 6 emulating indicator is required for each sterilization cycle time and temperature used, so a clinic running several cycle types needs a matched Type 6 product for each one.
Which class of chemical indicator goes inside every package
An internal chemical indicator is required inside each package, container or bundle, placed in the area judged least accessible to steam penetration, and the class is chosen according to the parameters being measured and the precision needed. Type 4, Type 5 and Type 6 can all serve as the internal indicator; the choice is about what the clinic wants the indicator to report, not about whether one is required.
Can a Class 5 or Class 6 indicator release a load without quarantine
Public Health Ontario's guidance allows evaluation of a Class 5 or Class 6 chemical indicator together with the specific cycle physical parameters to justify releasing routine loads where quarantine pending the biological indicator result is not possible. The same guidance's class table states that a Class 6 emulating indicator cannot be used to release loads that do not contain implants. Given the two readings, the conservative approach uses a Type 5 with the cycle physical parameters and quarantines implant loads regardless.
Do implant loads have different indicator requirements
Implantable devices must be quarantined until the biological indicator result is available, and a biological indicator is to be included in every load containing implantable devices. A chemical indicator, whatever its type, is not a substitute for that quarantine and does not release an implant load.
What does ISO 11140-6 cover
ISO 11140-6:2022 covers Type 2 indicators and process challenge devices for use in performance testing of small steam sterilizers conforming to EN 13060. It addresses equipment performance testing rather than pack-level internal monitoring, so it does not change what a clinic places inside a package.
CliniEco Medical distributes in Canada under MDEL #35334.
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