Incontinence Product Odour Control Technology in Canada vs the US: Which Mechanism Does What?
Every odour problem in an incontinence product starts with a reaction, not with a liquid. Urine is largely water and urea, and urea on its own has almost no smell. The smell appears when bacteria in the used product release urease, the enzyme that hydrolyses urea into ammonia and carbonate, lifting the pH of the core as it goes. That is why a brief or an underpad can be changed on time and still leave a room smelling, and it is why the products that control odour well are the ones that interrupt the chemistry rather than the ones that smell of perfume.
This reference guide covers the odour-control technologies used in adult absorbent products, the laboratory evidence for each, the absorbency and care requirements that apply in Canada and the United States, and the specification lines a facility can actually measure.
What makes a used incontinence product smell?
Urea hydrolysis is the driver. Urease-producing bacteria — among them Proteus mirabilis, Escherichia coli and Enterococcus faecalis — split urea into ammonia and carbamate, and the carbamate then breaks down further into another molecule of ammonia and bicarbonate. The net effect on the product is a rise in pH and a steady release of volatile ammonia, which is what the nose registers.
ODOUR BUILD-UP IN A CONTROLLED MODEL
| Elapsed time in the used product | Ammonia concentration at core pH 6.0 |
|---|---|
| 6 hours | 200 to 300 parts per million |
| 8 hours | 1,500 to 1,600 parts per million |
Those figures come from a laboratory method developed specifically to give incontinence product developers a way to measure malodour before clinical use: synthetic urine inoculated with bacteria was added to test pieces cut from the crotch area of disposable products, and bacterial growth and bacterially formed ammonia were then measured over time.
The second thing to understand is that "odour" is not one smell. When a trained sensory panel characterised used disposable absorbent products from 14 residents in geriatric nursing homes, it built a ten-attribute odour wheel and found that the used products divided into five odour classes, with descriptors ranging from sweetish through urinal to ammonia and smoked. Two products that both read as "smelly" to a care aide may be producing quite different volatiles, and a single fragrance will not neutralise both.
The practical consequence: odour intensity is a function of bacterial load, core pH and dwell time. Only two of those three are properties of the product you buy.
Which odour-control technologies change the chemistry?
There are six families of feature that appear in adult absorbent products, and they do not all work the same way. The table separates the ones that change the reaction from the ones that merely hide its result.
| Mechanism | How it works | Where it sits in the product | Evidence strength |
|---|---|---|---|
| Superabsorbent polymer core | Binds liquid into a gel so the surface layer stays dry and bacteria have less free water | Absorbent core | Established and near-universal |
| Acidic or pH-buffered core | Holds the core near pH 4.5 to 4.9, so urease-driven ammonia production is suppressed | Absorbent core | Measured in a controlled laboratory model |
| Odour-adsorbing fillers | Binds volatile amines and sulphur compounds onto carbon, zeolite or cyclodextrin surfaces | Distribution layer or core | Product-specific and variable |
| Antimicrobial additives | Reduces the bacteria that convert urea to ammonia | Core | Mixed results by agent |
| Fluid-barrier backsheet and leak guards | Keeps urine, and the volatiles above it, inside the product | Backsheet and leg cuffs | Established |
| Fragrance | Masks the smell without lowering ammonia | Anywhere in the product | Cosmetic only |
The pH line is the one worth dwelling on, because it is measurable. In the controlled model above, holding the product's superabsorbent at pH 6.0 allowed ammonia to climb from a few hundred parts per million at six hours to roughly 1,500 to 1,600 parts per million at eight hours. Dropping the same core to pH 4.5 or 4.9 significantly inhibited bacterial growth, in most cases at both the six-hour and twelve-hour readings, and the effect was strongest at pH 4.5. This is a pH effect on bacterial metabolism, not a deodorising claim.
Antimicrobial additives are less predictable. In the same work, chlorhexidine produced a significant inhibitory effect on E. coli and E. faecalis and, by twelve hours, on P. mirabilis. Polyhexamethylene biguanide and thymol gave results that varied by organism and time point. A supplier claiming broad antimicrobial odour control should be able to say which organisms were tested and at what concentration.
Filler chemistry is real but easy to overstate. Activated carbon, zeolites and cyclodextrins all have documented capacity to bind small volatile molecules, and combination odour-control materials have been described in the patent literature for absorbent articles. What the literature does not support is a claim that any one filler removes ammonia as effectively as pH control does, so a product specification that lists a filler without a pH target is aimed at the wrong variable.
Finally, two features that are constantly confused with odour control. A fragrance is a legitimate consumer preference but it does not lower the ammonia level, and a wetness indicator is not an odour feature at all — it is a cue that triggers the change that does the work.
Do Canada and the United States handle incontinence products the same way?
This is where buyers most often import a rule from the wrong jurisdiction. The two countries do not regulate absorbent incontinence products through the same instrument, and a requirement that is federal in one country is provincial in the other.
| Item | Canada | United States |
|---|---|---|
| Care requirement for residents in long-term care | Provincial. Ontario homes operate under the Fixing Long-Term Care Act, 2021 and its General regulation, O. Reg. 246/22, with continence care managed through the resident care plan | Federal. 42 CFR 483.25 requires a facility to provide the care and services needed to maintain or improve bladder and bowel function, and surveyors cite it under tag F690 |
| Device entry that names the product form | A Canadian buyer should not expect a device licence number printed on an absorbent brief or underpad; where a product does carry one, the number can be checked in the Medical Devices Active Licence Listing | 21 CFR 876.5920 names a protective garment for incontinence as a Class I device, exempt from premarket notification subject to the limitations in 876.9, product code EYQ |
| Absorbency evaluation method | ISO 15621 and ISO 11948-1 are the reference methods used in product evaluation | The same international methods are used; packaging frequently quotes a vendor-defined millilitre rating instead |
| Federal odour-control performance requirement | None | None |
| Scale of the care requirement | Set by each province, so a policy valid in Ontario is not automatically valid in British Columbia or Quebec | Set nationally through the Conditions of Participation, so the same tag applies in every state |
Two errors follow from that table. The first is treating a United States device entry as if it settled a Canadian question. The 876.5920 entry tells a United States buyer that a garment form does not need a premarket submission; it says nothing about Canadian requirements, and it does not create an absorbency or odour standard on either side of the border. The second is treating an Ontario rule as a national one. Ontario's long-term care regulation is provincial legislation, and Canada has no equivalent of the single federal Conditions of Participation that govern United States nursing facilities.
What both countries do share is the international standards base. ISO 15621, reissued as a fourth edition in February 2026, gives general guidelines on evaluating absorbent incontinence products for urine, faeces or both. ISO 11948-1 describes whole-product testing for the absorption capacity of the absorbent core of a body-worn urine-absorbing aid. Neither document is a Canadian rule or a United States rule; both are evaluation frameworks that a procurement team can require a supplier to test against, in either country.
How is absorbency measured, and does the method differ between Canada and the US?
The method question matters more than the number, because the number is not standardised.
| Rating basis | What it actually tells you | The caveat a buyer should note |
|---|---|---|
| Vendor millilitre rating on the case | The capacity the supplier chooses to quote, often 3,000 mL or 5,000 mL | No jurisdiction mandates a single method, so figures are not comparable between brands |
| ISO 11948-1 whole-product testing | The absorption capacity of the absorbent core of a body-worn aid | A laboratory method; it does not predict wear time on a mobile resident |
| ISO 15621:2026 evaluation framework | How to structure a product evaluation for urine, faeces or both | Guidance rather than a single pass-or-fail limit |
A facility comparing two cases of briefs therefore gets more signal from three operational measures than from the printed capacity: the change interval the product actually supports, the leak and complaint rate over a trial period, and the pack count inside the case. A case that holds fewer but larger packs changes the storage and restocking maths just as much as a change in absorbency does.
Which odour-control feature should a facility write into a specification?
Write specifications that a vendor can answer with a number or a document rather than an adjective. Five lines cover most of the field.
- Core pH target range, with the supplier stating the range and how it is maintained.
- Superabsorbent content or construction, so that a change in core build is visible on the invoice rather than discovered on the ward.
- Odour-adsorbing filler, named specifically if one is claimed, together with the organisms or volatiles it was tested against.
- Wetness indicator and leak-guard configuration, because these determine whether the change routine can be executed reliably at night.
- Test method behind any absorbency figure, ideally ISO 11948-1 or an evaluation carried out under ISO 15621:2026.
Then pair the specification with the routine. The evidence above is unambiguous that ammonia accumulates with time in the used product, so the interval between changes is a clinical variable, not an administrative one. A pH-controlled core extends the window in which a change is still early; it does not remove the need to make the change.
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. Absorbent products for facilities are grouped in the incontinence care collection, including 60 x 90 cm five-layer underpads with a SAP core, 4,000 mL adult incontinence briefs with a wetness indicator and 5,000 mL overnight briefs for night-time care.
References and standards cited
- ISO 15621:2026, Absorbent incontinence products for urine, faeces, or both — General guidelines on evaluation (fourth edition, published February 2026) (link checked 27 September 2026)
- ISO 11948-1:1996, Urine-absorbing aids — Part 1: Whole-product testing (link checked 27 September 2026)
- ISO 15621:2026 publication record and edition history (link checked 27 September 2026)
- Electronic Code of Federal Regulations, 21 CFR 876.5920 — protective garment for incontinence (link checked 27 September 2026)
- Cornell Legal Information Institute, 21 CFR 876.5920 — protective garment for incontinence (link checked 27 September 2026)
- United States Food and Drug Administration, CFR search result for 21 CFR 876.5920 (link checked 27 September 2026)
- United States Food and Drug Administration, product classification for code EYQ (protective garment for incontinence) (link checked 27 September 2026)
- Cornell Legal Information Institute, 42 CFR 483.25 — quality of care in long-term care facilities (link checked 27 September 2026)
- Electronic Code of Federal Regulations, 42 CFR 483.25 — quality of care (link checked 27 September 2026)
- Ontario, Fixing Long-Term Care Act, 2021, S.O. 2021, c. 39 (link checked 27 September 2026)
- Ontario Regulation 246/22 (General) under the Fixing Long-Term Care Act, 2021 (link checked 27 September 2026)
- Widén H, Alenljung S, Forsgren-Brusk U, Hall G. Sensory characterization of odors in used disposable absorbent incontinence products. J Wound Ostomy Continence Nurs. 2017;44(3):277-282 (link checked 27 September 2026)
- Forsgren-Brusk U, Yhlen B, Blomqvist M, Larsson P. Method for bacterial growth and ammonia production and effect of inhibitory substances in disposable absorbent hygiene products. J Wound Ostomy Continence Nurs. 2017;44(1):78-83 (link checked 27 September 2026)
- Reviews in Environmental Science and Bio/Technology, the molecular processes of urea hydrolysis in relation to ammonia emissions (link checked 27 September 2026)
- Zeolites as ingredients of medicinal products, National Library of Medicine full-text record (link checked 27 September 2026)
- Public Health Ontario, infection prevention and control resource hub for health care settings (link checked 27 September 2026)
- Canadian Centre for Occupational Health and Safety, OSH Answers fact sheet library (link checked 27 September 2026)
Related Reading
- Adult Briefs Odour Control: Absorbent Cores and Resident Dignity
- Odor Control in LTC: How Underpad Core Design Manages Ammonia
- Incontinence-Associated Dermatitis in Canadian LTC: Prevention and Product Selection
- Incontinence care collection — absorbent products for facilities and home care
- Learning hub — procurement and compliance guides
Frequently Asked Questions
Why do adult incontinence products still smell after a change?
Because the smell is produced by bacteria, not by the product. If a brief or underpad is changed before the bacteria have converted the urea in the urine into ammonia, the odour has not formed yet. If it is left on, or if urine is left in the bed pad under the resident, the same reaction continues in the fabric and the room. Changing on a schedule that keeps the product from sitting wet is the single largest odour-control measure available to a care team, and the absorbent core is what buys the time between changes.
Which odour-control mechanism makes the largest difference in an absorbent brief?
Keeping the core acidic makes the largest measurable difference, because it attacks the reaction that produces the smell rather than the smell itself. In a laboratory model, adjusting the superabsorbent in an incontinence product from pH 6.0 down to pH 4.5 and 4.9 significantly inhibited bacterial growth at both 6 and 12 hours, with the strongest effect at pH 4.5. The same model recorded ammonia at 200 to 300 parts per million after 6 hours and 1,500 to 1,600 parts per million after 8 hours at pH 6.0. Perfume does nothing to those numbers.
Is there a Canadian standard for incontinence product absorbency?
There is no Canadian-only absorbency standard. Canada uses the international evaluation methods, principally ISO 15621, which was reissued as a fourth edition in February 2026, and ISO 11948-1, which sets out whole-product testing for the absorbent core of a body-worn aid. Vendors quoted against the older ISO 15621:2017 edition are citing a superseded document. Ask which test method produced the millilitre number on the case.
How is absorbency measured, and why do the millilitre ratings differ between brands?
No jurisdiction mandates one millilitre rating method for absorbent incontinence products, so a printed figure such as 3,000 mL or 5,000 mL is a vendor-defined capacity, not a comparable performance grade. ISO 11948-1 describes a laboratory method for whole-product absorption capacity, and ISO 15621:2026 describes how a product evaluation should be structured. Two products with the same printed number can therefore behave differently once worn, which is why facilities should compare change intervals and leakage complaints rather than the printed figure alone.
Does the United States regulate adult incontinence products as medical devices?
Partly. The United States Code of Federal Regulations contains a device entry for a protective garment for incontinence at 21 CFR 876.5920, described as absorbent padding with a fluid barrier that protects an incontinent patient's clothing. It sits in Class I, is exempt from premarket notification subject to the limitations in 876.9, and carries product code EYQ. That entry describes the garment form of the product; it does not set an odour-control or absorbency performance requirement.
Does Canada's federal single-use plastics prohibition cover incontinence products?
No. The federal prohibition targets six listed single-use plastic categories — checkout bags, cutlery, foodservice ware, ring carriers, stir sticks and straws. Absorbent incontinence garments and underpads are not among them, so a facility cannot rely on that regulation to justify a material change, and equally should not be told that a brief must be biodegradable because of it. Provincial waste rules and each facility's own sustainability policy are where those choices are actually made.
Should a care home write pH control into an incontinence product specification?
It is a reasonable line to add, provided it is written as a verifiable property rather than a marketing phrase. Ask for the target pH range of the absorbent core, the SAP content or construction, and whether the core uses odour-adsorbing fillers such as activated carbon or zeolite. Then pair the specification with a change interval, a wetness-indicator check, and a documented par level, because the physical routine is what stops the odour reaction from running to completion.
Where can a clinic or care home order incontinence supplies in case quantities?
Institutional buyers normally order by case or by pallet rather than by the single pack, and the ordering route differs from a consumer checkout. Case counts, pallet configurations and account setup are handled on the wholesale side, and the institutional catalogue lists the absorbent lines that are stocked for facilities, home care agencies and multi-site operators. Ask for the case configuration and the pack count inside it before you compare two quotes, because the same product can be listed in different case sizes.
Last updated: September 2026. CliniEco Medical is a licensed medical device establishment (MDEL #35334).
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