AAMI PB70 Testing Explained: How Gown Levels Are Measured

Quick Summary: When a Canadian long-term care home or clinic buys isolation gowns, the label says "Level 1" or "Level 2" — but what actually separates those levels is a set of standardized liquid barrier tests defined by ANSI/AAMI PB70. This article explains how hydrostatic pressure and impact penetration tests work, what each of the four levels requires, why a PB70 level is not the same as a viral barrier claim, and what a procurement manager should verify before ordering. Read time: 8 minutes.

1. Why "Level" Is a Test Result, Not a Marketing Term

In healthcare procurement, the phrase "Level 2 isolation gown" is used so casually that it is easy to forget what the level actually represents. AAMI PB70 is not a brand standard or a quality rating. It is a classification system built on specific, repeatable laboratory tests that measure how well a gown material resists liquid penetration under defined conditions.

The formal title is ANSI/AAMI PB70, Liquid barrier performance and classification of protective apparel and drapes intended for use in health care facilities. It was developed to give infection control teams and purchasers a common language: when a supplier says "Level 2," they are making a test-based claim about fluid resistance, not an opinion.

For a Canadian buyer — whether a long-term care director, a clinic manager, or a hospital procurement specialist — understanding what the tests actually do matters because it determines which product fits which task. A Level 1 gown is not "worse" than a Level 3 gown; it is designed for a different exposure scenario. Buying the wrong level is both a compliance and a cost problem.

2. The Two Core Tests in AAMI PB70

PB70 classifies gowns using two primary test methods, each simulating a different way liquid reaches a caregiver:

The two tests capture different failure modes. A gown that resists a slow water column may still let a high-velocity splash through, and vice versa. That is why PB70 requires both — a gown cannot claim a level based on a single favorable result.

3. The Four Levels and Their Thresholds

ANSI/AAMI PB70 defines four barrier levels, from minimal to high liquid resistance:

The exact numerical thresholds are defined in the standard itself, which is available from AAMI and through standards distributors. What matters for procurement is the direction: as the level increases, the gown is tested against progressively more demanding liquid exposure.

In practice, most long-term care and clinic tasks fall in the Level 1 to Level 3 range. Level 4 gowns are a different product category — surgical gowns — with substantially different construction and cost.

4. Level 2 in Long-Term Care: The Daily Workhorse

Long-term care homes in Canada are the largest single buyer of Level 2 gowns in the medical supply chain. The reason is workflow: LTC staff perform a high volume of personal care — toileting, bathing, wound care, feeding assistance — where fluid exposure is real but rarely at surgical intensity.

A 40 gsm SMMS (spunbond-meltblown-meltblown-spunbond) gown is a common construction for this category. The meltblown layers are what create the fluid barrier; the spunbond layers provide strength and comfort. For LTC operators, the practical questions are whether the gown passes the Level 2 thresholds, how the material feels over a full shift, and whether the price per gown fits a tight per-resident-day budget. A product like the CliniEco SMMS 40 gsm Level 2 gown is an example of this construction category.

Infection prevention guidance from public health authorities — including PHAC's expectations for infection prevention and control programs in healthcare settings — treats appropriate PPE selection as a core expectation. For LTC homes, that means having the right level of gown available for the right task, not just "having gowns."

5. Why PB70 Level Is Not a Viral Barrier Claim

This is the most common misunderstanding in gown procurement. AAMI PB70 levels classify liquid barrier performance. They do not, by themselves, certify that a gown blocks viruses or bloodborne pathogens.

Viral penetration is a separate test — ASTM F1671 (or the international equivalent ISO 16604) — which challenges the material with a bacteriophage surrogate under pressure and measures whether virus-sized particles pass through. Level 4 in the PB70 framework is the level that requires viral penetration testing; Levels 1 through 3 are defined by liquid resistance only.

That distinction is not academic. In infection control practice, the risk chain for bloodborne pathogens involves both the fluid carrying the pathogen and the pathogen itself. A gown's fluid resistance determines whether contaminated liquid reaches the wearer's clothing or skin; viral penetration testing adds evidence about the barrier's performance against pathogen-sized particles. Procurement teams should ask which test standard supports the claim they are relying on.

6. Material Construction Drives the Test Result

You cannot infer a gown's PB70 level from its appearance. Two gowns that look identical can test differently because of the fabric structure:

• Fabric layers: SMMS and SMS constructions use meltblown layers as the barrier; more or better meltblown content improves fluid resistance.
• Fabric weight (gsm): Higher weight generally improves barrier performance, but the layer structure matters more than weight alone.
• Seams and closures: The gown is only as good as its weakest point. Knit cuffs, secure neck closures, and reinforced seams matter for real-world protection.
• Coverage: A gown that leaves gaps at the back or arms creates exposure routes that no fabric test can fix.

For buyers, the implication is to verify the product's tested level rather than assume it from material weight. A 40 gsm SMMS gown can be manufactured to meet Level 2 — and should be labelled as such based on testing, not on construction alone.

7. Canadian Compliance Context: What Regulators Expect

In Canada, isolation gowns are regulated as medical devices under the Medical Devices Regulations (SOR/98-282). The regulatory expectation is that claims made about a device — including barrier level claims — are substantiated. A supplier marketing a gown as "Level 2" should be able to point to the underlying test data.

Beyond device regulation, infection prevention expectations come from provincial public health requirements, accreditation standards, and occupational health and safety duties. Employers have a general duty under provincial OHS legislation to provide appropriate PPE for the tasks staff perform. In long-term care, that duty interacts directly with outbreak control protocols — gowns are one of the primary controls during respiratory and gastrointestinal outbreaks in Canadian LTC homes.

Documentation is the practical deliverable: keep product test documentation, lot numbers, and purchase records on file. When a public health inspector or an accreditation surveyor asks what level of gown you are using and why, the answer should reference the product's tested classification, not a vague memory of what was ordered.

8. Sustainability in Gown Procurement

Healthcare institutions in Canada are under growing pressure to reduce the environmental footprint of single-use products. Disposable isolation gowns are a high-volume item, and the waste stream is significant. Options include gowns made from biodegradable materials — PLA-based non-woven isolation gowns are one example that has entered the Canadian market — and procurement policies that match gown level to task so that heavier, costlier gowns are not used where a lighter level is sufficient.

Sustainability organizations in the healthcare sector, such as Practice Greenhealth and Health Care Without Harm, have documented the value of optimizing PPE use — not just swapping materials, but aligning product selection with actual clinical need. For gowns, that means reviewing whether Level 1 gowns are used for low-exposure tasks, Level 2 for daily care, and Level 3+ only where the procedure demands it. Biodegradable PLA isolation gowns are one option entering the Canadian market for facilities prioritizing waste reduction.

9. Procurement Checklist: What to Ask a Gown Supplier

1. Ask for the test report: the product's PB70 level should be backed by test documentation, not just a label.
2. Confirm the test standard: ANSI/AAMI PB70 classification; ask whether viral penetration testing (ASTM F1671 / ISO 16604) applies to the product.
3. Check the construction: fabric layers, weight in gsm, knit cuffs, and closure design.
4. Verify medical device status: confirm the supplier documents the product's regulatory status under the Medical Devices Regulations.
5. Match level to task: a facility standard that says which gown level is used for which care category prevents both over- and under-specification.
6. Confirm sizing and coverage: staff must fit the gown properly; one-size products may not suit all tasks.
7. Review stock continuity: outbreak response cannot wait for a restock; confirm buffer inventory and lead times.

Facilities that standardize this way — with a documented gown matrix tied to tested levels — tend to have smoother inspections and better cost control than facilities that order by habit.

10. FAQ

Q1: What does AAMI PB70 stand for?

ANSI/AAMI PB70 is the standard for liquid barrier performance and classification of protective apparel and drapes used in health care facilities. It defines the four barrier levels that gown labels refer to.

Q2: What is the difference between Level 1 and Level 2 gowns?

Level 1 provides the lowest liquid barrier and is for minimal fluid exposure. Level 2 is tested against higher water pressure and impact penetration, making it suitable for moderate fluid exposure such as LTC personal care and routine clinical tasks.

Q3: Does a Level 3 gown block viruses?

Not by itself. PB70 levels measure liquid barrier performance. Viral penetration is tested separately under ASTM F1671 or ISO 16604, which is required for Level 4 classification.

Q4: What is a 40 gsm SMMS gown?

SMMS stands for spunbond-meltblown-meltblown-spunbond, a four-layer non-woven construction. The meltblown layers provide fluid resistance. 40 gsm refers to the fabric weight in grams per square metre.

Q5: What level of gown do long-term care homes need?

Most LTC personal care tasks are covered by Level 2 gowns. Level 1 can be appropriate for low-exposure tasks, and Level 3+ should be reserved for procedures with significant splashing. Facilities should document their gown matrix by task.

Q6: Are isolation gowns regulated by Health Canada?

Yes. Isolation gowns sold as medical devices in Canada are regulated under the Medical Devices Regulations (SOR/98-282), and barrier claims should be substantiated with test data.

Q7: How can I verify a gown's PB70 level?

Ask the supplier for the product's test documentation from an accredited laboratory. The level should reference ANSI/AAMI PB70 and identify which tests were performed.

Q8: Are there biodegradable isolation gown options?

Yes. PLA-based non-woven isolation gowns are available in the Canadian market as a more sustainable alternative. Verify that the product still meets the barrier level required for your tasks before switching.

11. Final Word for Canadian Buyers

The gown level on a box is a test result, and buying decisions should treat it that way. Understand the two PB70 tests, match the level to the task, keep the documentation, and do not confuse fluid resistance with viral barrier claims. That framework turns a routine PPE order into a defensible infection control decision.

CliniEco Medical supplies tested isolation gowns to Canadian LTC homes, clinics, and healthcare facilities — including SMMS 40 gsm Level 2 gowns for daily care and non-woven Level 1 gowns for low-exposure tasks. If your facility is reviewing its gown program or wants a bulk quote, contact our sales team for product documentation and pricing.

Last updated: August 16, 2026. This article is for general information and does not constitute medical, legal, or regulatory advice. Always follow your facility's infection prevention protocols and applicable provincial requirements.

Also read: compare isolation gown standards (ASTM F2407 vs AAMI PB70) in our pillar guide.

References

1. AAMI. ANSI/AAMI PB70 — Liquid barrier performance and classification of protective apparel and drapes intended for use in health care facilities. https://www.aami.org/
2. ASTM International. Standards for protective clothing and medical textiles (including F1670 and F1671). https://www.astm.org/
3. ISO. Standards catalogue — Protective clothing (including ISO 16604). https://www.iso.org/
4. Government of Canada. Medical Devices Regulations (SOR/98-282). https://laws-lois.justice.gc.ca/eng/regulations/SOR-98-282/
5. Health Canada. Medical devices — how devices are approved and authorized in Canada. https://www.canada.ca/en/health-canada/services/drugs-health-products/medical-devices.html
6. Public Health Agency of Canada. Infection prevention and control. https://www.canada.ca/en/public-health/services/infection-prevention-control.html
7. World Health Organization. Infection prevention and control. https://www.who.int/teams/integrated-health-services/infection-prevention-control
8. Antimicrobial Resistance & Infection Control (Springer, open access). https://link.springer.com/journal/13756
9. Journal of Hospital Infection (Elsevier). https://www.sciencedirect.com/journal/journal-of-hospital-infection
10. American Journal of Infection Control (Elsevier). https://www.sciencedirect.com/journal/american-journal-of-infection-control
11. Infection Control & Hospital Epidemiology (Cambridge). https://www.cambridge.org/core/journals/infection-control-and-hospital-epidemiology
12. Emerging Infectious Diseases (CDC). https://wwwnc.cdc.gov/eid/
13. Practice Greenhealth. Sustainable healthcare procurement resources. https://practicegreenhealth.org/
14. Health Care Without Harm. Climate-smart healthcare and sustainable procurement. https://noharm.org/
15. Canadian Centre for Occupational Health and Safety (CCOHS). PPE and occupational health resources. https://www.ccohs.ca/

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