"Are these sterile?" and "is this aseptic?" get asked in the same breath at the supply room door, but they are answered by two different documents and they carry two different obligations. Sterile describes the microbial state of an item after a validated process; aseptic describes the practices that keep contamination away from a patient — and from that item once its packaging is opened. Mixing the two costs clinics money at the purchase order stage and credibility at inspection stage. This article sets out the definitions word-for-word from the documents Canadian dental and medical clinics are held to, then converts the difference into a one-page protocol check you can print and post.
For the short glossary version of the same distinction, see sterile vs sterilized vs aseptic: the terms clinics mix up.Quick facts
| Question | Short answer | Source |
|---|---|---|
| What does "sterile" mean? | Free from viable microorganisms | ISO 11737-1:2018, Introduction |
| What makes an item sterile? | A validated process, not an inspection | CDC Guideline for Disinfection and Sterilization in Healthcare Facilities, 2008, Definition of Terms |
| How sterile is "sterile"? | FDA expects a sterility assurance level (SAL) of 10⁻⁶ for devices labelled as sterile (10⁻³ only for contact with intact skin) | FDA, Submission and Review of Sterility Information in 510(k) Submissions for Devices Labeled as Sterile, p.9 |
| What does "asepsis" mean? | The absence of pathogenic microorganisms | RCDSO, Infection Prevention and Control in the Dental Office (v3), Glossary |
| What is "aseptic technique"? | A term used to describe practices that minimize the risk of microbial contamination | RCDSO, IPAC v3, Glossary |
| Who protects the sterile item after the pack is opened? | Aseptic technique | CDC 2008, p.75 |
Why are "sterile" and "aseptic" defined in different documents?
Read the definitions side by side and the confusion disappears.
Sterile is a state. ISO 11737-1:2018 opens with the sentence that the rest of the sterilization standards assume: "A sterile health care product is one that is free of viable microorganisms" (ISO 11737-1:2018, Introduction). Nothing about that sentence is achievable by looking at an item, wiping it, or storing it carefully. It is a state produced by a process and then preserved or lost.
Sterilization is the process. The CDC's national guideline defines it this way: "Sterilization describes a process that destroys or eliminates all forms of microbial life and is carried out in health-care facilities by physical or chemical methods" (CDC Guideline for Disinfection and Sterilization in Healthcare Facilities, 2008, p.8). The same page adds the sentence every clinic manager should read twice: "Sterilization is intended to convey an absolute meaning; unfortunately, however, some health professionals and the technical and commercial literature refer to 'disinfection' as 'sterilization' and items as 'partially sterile.'" There is no partially sterile item. There is a sterilized item, or there is an item that has been cleaned and disinfected.
Ontario's dental standard uses the word "validated" in the definition it gives registrants: "Sterilization: A validated process that kills all pathogenic microorganisms, including bacteria, fungi, viruses and spores" (RCDSO, IPAC v3, Glossary, p.37). Provincial public health guidance in the same province defines it by required outcome: "Sterilization results in the destruction of all forms of microbial life including bacteria, viruses, spores and fungi. Equipment/devices must be cleaned thoroughly before effective sterilization can take place" (PHO/PIDAC provincial guidance on cleaning, disinfection and sterilization, 3rd ed. (May 2013), Glossary).
How sterile is sterile? It is a probability, not an absolute. For devices labelled as sterile, the FDA expects the sponsor to state a SAL of 10⁻⁶ — the expected probability of a surviving microorganism on the individual product after exposure to a valid sterilization process — unless the device only contacts intact skin, where 10⁻³ is accepted (FDA sterility guidance, p.9). That is why nobody cultures the instruments to prove a load is sterile. The proof is the process record: cycle parameters, chemical indicators, and a biological indicator result.
Asepsis is a condition, and aseptic technique is the set of practices that produce it. The RCDSO glossary defines "Asepsis" as "the absence of pathogenic (i.e. disease-producing) microorganisms" and "Aseptic technique" as "a term used to describe practices that minimize the risk of microbial contamination." Sterile excludes all viable microorganisms; asepsis is defined against pathogens. The same standard spells out what aseptic technique means in a dental operatory: "Aseptic technique is a term used to describe practices that prevent microbial contamination. These practices include environmental cleaning, effective hand hygiene, wearing appropriate clinical attire (e.g. gloves, protective eyewear, masks, gowns), proper handling of clean instruments, wrapping and sterilization, proper handling of sterile instruments as they are unwrapped, preventing sterile instruments from being contaminated from environmental sources and properly administering medicines" (RCDSO, IPAC v3, p.36).
That paragraph alone is worth pinning above the reprocessing bench: wrapping and sterilization are listed as parts of aseptic technique, not as alternatives to it.
Table 1 — Term map
| Term | What it describes | Where it is defined | Decision it drives |
|---|---|---|---|
| Sterile | The microbial state of an item, free from viable microorganisms | ISO 11737-1:2018, Introduction | Whether a critical item can be used on tissue — with a SAL expectation of 10⁻⁶ (FDA, p.9) |
| Sterilization | A validated process that destroys all forms of microbial life | CDC 2008, p.8; RCDSO IPAC v3, Glossary | What your autoclave cycle, monitoring and records must prove |
| Sterilized | An item that has completed a validated sterilization process | CDC 2008, p.8 (contrast with "partially sterile") | Label wording on in-house and purchased packs |
| Asepsis | The absence of pathogenic microorganisms | RCDSO IPAC v3, Glossary | The target condition at the point of use |
| Aseptic technique | Practices that minimize the risk of microbial contamination | RCDSO IPAC v3, Glossary and p.36 | Hand hygiene, barriers, transfer forceps, handling of opened packs |
| Surgical aseptic technique | Practices that render and maintain objects and the area maximally free of microorganisms and create a sterile field | RCDSO IPAC v3, p.36 | Whether a procedure can claim a sterile field at all |
| Disinfection | A process that eliminates many or all pathogenic microorganisms, except bacterial spores, on inanimate objects | CDC 2008, p.8 | Surface and equipment decisions — never a substitute for sterilization of critical items |
| Sterility assurance level (SAL) | The expected probability of a surviving microorganism on an individual product after a valid sterilization process | FDA sterility guidance, p.9 | How cycle validation is described to a buyer or an inspector |
What a cleaner is allowed to claim
Cleaning equipment sits on the same spectrum, and it is defined just as carefully. Provincial guidance defines an ultrasonic washer as "a machine that cleans medical equipment/devices by the cavitations produced by ultrasound waves," and keeps it distinct from a washer-disinfector, which "provides low-level disinfection" (PHO/PIDAC, 3rd ed., Glossary). The international washer-disinfector standard draws its own line: it covers machines "intended to be used for cleaning and disinfection of reusable medical devices" and states that it "does not include requirements for machines which are intended to sterilize the load, or which are designated as 'sterilizers' and addressed in other standards" (ISO 15883-1:2024, Abstract and Scope).
Practical translation: an ultrasonic cleaner cleans. It does not disinfect and it does not sterilize, and no purchase order should describe it as doing either.
The order of operations: sterile first, aseptic keeps it that way
The CDC guideline puts the handoff in one sentence: "Following the sterilization process, medical and surgical devices must be handled using aseptic technique in order to prevent contamination" (CDC 2008, p.75). Sterility is the condition you manufacture; asepsis is the behaviour that stops you from losing it before the instrument reaches tissue.
The same page gives the failure mode in plain language: "Sterile items that become wet are considered contaminated because moisture brings with it microorganisms from the air and surfaces." A pack that was perfectly processed and then stored under a sink, or carried through a wet decontamination area, is not sterile any more — and no certificate fixes it.
Two operational consequences follow, and they explain most assignment-of-blame arguments in a clinic:
- Process evidence is documented; handling evidence is observed. Your biological indicator and cycle log prove the process. Nothing in the log proves how the pack was opened.
- Aseptic technique is a team obligation, not a personal habit. The RCDSO standard states it directly: "Maintaining aseptic technique is a cooperative responsibility of the entire dental team" (IPAC v3, p.36).
Where the two words get mixed up — and what it costs
1. Purchase orders that describe "aseptic" products. Aseptic is not a product attribute you can buy; it is what your team does with what you buy. Exam gloves, for example, are supplied non-sterile on purpose, because a routine exam does not require a sterile field. The distinction matters most when the item must be reprocessed: ISO 17664-1:2021 "specifies requirements for the information to be provided by the medical device manufacturer for the processing of critical or semi-critical medical devices (i.e. a medical device that enters normally sterile parts of the human body or a medical device that comes into contact with mucous membranes or non-intact skin)" (ISO 17664-1:2021, Abstract). If a supplier cannot provide validated processing instructions, your clinic cannot build a compliant cleaning and sterilization routine for that device — and "it is a good quality instrument" is not a substitute for instructions.
2. "Sterile" labels written in-house without monitoring. A pack is not sterile because the pouch said so. Ontario's standard defines a biological indicator as "a device that is used to monitor the sterilization process, which consists of a standardized population of bacterial spores known to be resistant to the mode of sterilization being monitored. BIs indicate that all the parameters necessary for sterilization were present" (RCDSO IPAC v3, Glossary). The BIs and chemical indicators are the evidence; the label is the summary.
3. Disinfection wearing the word sterilization. The CDC guideline names the habit. Provincial guidance adds the boundary: "Disinfection is the inactivation of disease-producing microorganisms. Disinfection does not destroy bacterial spores or prions" and washer-disinfectors "are not to be used for high-level disinfection" (PHO/PIDAC 3rd ed., pp.31 and 30). Critical items that contact sterile tissue or the vascular system must be sterile (CDC 2008, Critical Items).
4. Buying aseptic technique. Technique can be trained, audited and documented, but it cannot be purchased as a kit. What can be purchased is the equipment that makes the technique possible: a pouch sealer that produces a continuous seal, transfer forceps, indication tape, and packaging that keeps the barrier intact.
5. Treating the pack as the end of the process. Provincial guidance requires that "Once medical equipment/devices have been reprocessed, there must be a process to ensure that they can be differentiated from equipment/devices which have not been reprocessed" — external chemical indicators, labels or colour-coding (PHO/PIDAC 3rd ed., p.30). The CDC adds storage clearances that auditors check: sterile supplies stored 8–10 inches from the floor, 5 inches from the ceiling (18 inches from a sprinkler head) and 2 inches from outside walls, not under sinks or in wet locations (CDC 2008, p.75).
Table 2 — What each claim obliges you to do, by product line
| Product line | If the claim is "sterile" | If the practice is "aseptic" | Document to point to |
|---|---|---|---|
| Critical instruments and devices | A validated cycle, plus load monitoring and release records | Handling of the opened pack with transfer forceps and clean hands | CDC 2008, Critical Items; RCDSO IPAC v3, p.36 |
| Packaging and seals | Barrier intact, seal continuous, pack dry | Pack opened without touching the contents or the inner surface | PHO/PIDAC 3rd ed., Wrapping; CDC 2008, p.75 |
| Monitoring consumables | BI and CI results tied to the specific load | Indicators read and logged at the time of release, not later | RCDSO IPAC v3, Glossary (BI definition) |
| PPE | Sterile gloves only where a sterile field is claimed | Non-sterile exam gloves for routine care, donned immediately before the procedure | RCDSO IPAC v3, p.36; CDC 2008, p.75 |
| Cleaning chemistry and baths | Nothing — chemistry reduces bioburden; it does not sterilize | Bath solution changed at least daily, items fully immersed, rinsed before further reprocessing | RCDSO IPAC v3, p.20; PHO/PIDAC 3rd ed., p.29 |
| Transport, storage and waste | Items kept dry, differentiated from unprocessed items | Workflow from dirty to clean, single direction, with point-of-use containment | PHO/PIDAC 3rd ed., p.30; RCDSO IPAC v3, p.20 |
What should your written protocol check include?
Work down this list once, fix what is missing, then audit quarterly. Each line names the source you can show an inspector.
- Every reusable critical and semi-critical device has manufacturer processing instructions on file (ISO 17664-1:2021, requirements for manufacturer-provided processing information).
- Cleaning is a written protocol covering disassembly, sorting, soaking, physical removal of soil, rinsing, drying, inspection, lubrication and wrapping (PHO/PIDAC 3rd ed., Recommendation 38).
- Cleaning is audited on a regular basis, with a documented follow-up process for irregularities (PHO/PIDAC 3rd ed., Recommendation 39).
- Ultrasonic cleaning is used for devices with joints, crevices or lumens, with the manufacturer's instructions for use and maintenance followed, items fully immersed, and a thorough rinse before further reprocessing (PHO/PIDAC 3rd ed., p.29).
- Gross debris is removed before anything enters the ultrasonic bath, and the bath solution is changed daily or sooner if visibly soiled (RCDSO IPAC v3, p.20; PHO/PIDAC 3rd ed., p.29).
- Items are wrapped so that air removal, steam penetration and evacuation reach all surfaces before sterilization (PHO/PIDAC 3rd ed., Wrapping).
- In Ontario, a biological indicator in a process challenge device is used to test the sterilizer each day it is used — and for each type of cycle used that day (RCDSO IPAC v3, p.24).
- The sterilizer log book is kept at least 10 years from the date of the last entry, and the air removal test is run at the beginning of each day the sterilizer is used (RCDSO IPAC v3, p.24).
- Reprocessed items are distinguishable from unprocessed items by indicator, label or colour code (PHO/PIDAC 3rd ed., p.30).
- Sterile storage meets the clearance and dryness rules, and any pack that has become wet is treated as contaminated (CDC 2008, p.75).
- Hand hygiene is performed at the documented moments, including before an aseptic procedure and after glove removal (RCDSO IPAC v3, p.8).
- Transfer forceps are available at all times, and gloves are applied immediately before the procedure begins (RCDSO IPAC v3, p.36).
If two or three lines are open, the fix is usually documentation, not equipment. Our dental compliance hub collects the printable checklists that go with this one, and the sterilization monitoring collection lists the indicators and incubators that generate the records. Clinics that want a starting point for the monitoring and handling side can compare a 24-hour biological indicator 25-pack with a 5-pack trial for a single chair, and pair either with a dry-block incubator so the result is read on schedule instead of "when someone remembers."
Sources
- ISO 11737-1:2018, Sterilization of health care products — Microbiological methods — Part 1, Introduction
- CDC, Guideline for Disinfection and Sterilization in Healthcare Facilities, 2008 — Definition of Terms, p.8
- CDC, Guideline for Disinfection and Sterilization in Healthcare Facilities, 2008 — Critical Items, p.10
- CDC, Guideline for Disinfection and Sterilization in Healthcare Facilities, 2008 — storage and handling of sterile items, p.75
- RCDSO, Standard of Practice: Infection Prevention and Control in the Dental Office (v3)
- Public Health Ontario / PIDAC, provincial guidance on cleaning, disinfection and sterilization in all health care settings, 3rd ed. (May 2013)
- ISO 17664-1:2021, Processing of health care products — Information to be provided by the medical device manufacturer, Part 1: Critical and semi-critical medical devices
- ISO 15883-1:2024, Washer-disinfectors — Part 1: General requirements, terms and definitions and tests
- CSA Z314:23, Canadian medical device reprocessing in all health care settings (current edition listing)
- FDA, Submission and Review of Sterility Information in Premarket Notification (510(k)) Submissions for Devices Labeled as Sterile
- CliniEco Medical sterilization monitoring collection
Have a question about your own facility? Send it in and you will get a written answer specific to your setup, with the regulation or standard it is based on cited. Ask your compliance question.
Related reading
- Sterile vs sterilized vs aseptic: the terms clinics mix up — the short glossary version of this article, useful as a staff-room handout.
- Spaulding classification and disinfection levels explained — why critical, semi-critical and non-critical items are held to different end points.
- Instrument reprocessing workflow: clean, disinfect, sterilize — the chain that turns the definitions into a workflow.
- Aseptic technique in the exam room — what non-sterile supplies are for, and where the line sits.
- clinic consumables
- free Ontario sterilization compliance log
Frequently Asked Questions
Can an item be sterile but not aseptic?
Yes. Sterility is a state of the item after a validated process; asepsis is a condition maintained by technique. A pack can leave the sterilizer sterile and stop being sterile the moment it is stored wet, opened on a contaminated surface or handled with bare hands. The CDC guideline handles this directly, stating that after sterilization devices must be handled using aseptic technique to prevent contamination.
Is aseptic technique the same as sterile technique?
No. General aseptic technique describes practices that minimize the risk of microbial contamination. Surgical aseptic technique, as defined by the RCDSO standard, refers to practices that render and maintain objects and the surrounding area maximally free of microorganisms, prevent contamination of a wound, and create a sterile field. Most routine dental procedures use general aseptic technique; a claimed sterile field means the surgical version.
Does an ultrasonic cleaner disinfect or sterilize instruments?
Neither. Provincial guidance defines an ultrasonic washer as a machine that cleans medical equipment and devices by the cavitations produced by ultrasound waves, and keeps it separate from washer-disinfectors, which provide low-level disinfection. Cleaning always comes before disinfection or sterilization, and critical items must still be sterilized after cleaning.
How sterile is sterile, in numbers?
For a device labelled as sterile, the FDA expects a sterility assurance level of 10 to the power of minus 6, unless the device only contacts intact skin, where 10 to the power of minus 3 is accepted. SAL is a probability statement about the process, which is why load release is based on monitoring results and cycle records rather than on testing the instruments themselves.
What does this change on a purchase order?
Two things. First, stop using aseptic as a product attribute; it describes practice, not packaging. Second, for anything your clinic reprocesses, require manufacturer processing instructions that cover cleaning, disinfection, sterilization and any restrictions on reuse, because that is the information ISO 17664-1:2021 requires a manufacturer to provide for critical and semi-critical devices.
If a pack gets wet in storage, is it still sterile?
No. The CDC guideline states that sterile items which become wet are considered contaminated because moisture brings microorganisms from the air and surfaces with it. The pack should be reprocessed, and the storage area checked against the clearance rules for floor, ceiling, sprinkler heads, outside walls and wet locations.
Where does the provincial guidance sit relative to CSA Z314:23?
They overlap. Provincial guidance such as the PIDAC document sets out the practices and cites CSA standards by name, while CSA Z314:23 is the current consolidated national medical device reprocessing standard; its scope lists settings that include dental general and surgical facilities. Where a provincial college standard applies to your clinic, follow it, and use the CSA standard for the technical detail the college standard points to.
CliniEco Medical holds MDEL #35334.
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