Quick Summary: ASTM F1670 and ASTM F1671 are the two test methods that decide whether a gown material resists synthetic blood and bloodborne pathogens under pressure. EN 13795 covers the same ground from the European side, and AAMI PB70 turns all of it into the four-level ladder printed on gown packaging. This guide explains what each test actually does, how the results are reported, and how a Canadian clinic or LTC home can verify a gown claim before placing a bulk order.
A clinic buyer comparing gown listings sees two prices and two photographs. What separates the products sits in fine print nobody photographs: a level number, a test method, and a critical-zone diagram. Getting that fine print right is the difference between a gown that sheds a splash and a gown that has never been tested against anything.
Blood and body fluid exposure is not a hypothetical. It is the reason the US Bloodborne Pathogens standard exists as a numbered regulation with engineering and PPE controls attached to it (OSHA), and the reason Canadian guidance from Public Health Ontario treats gown selection as part of routine and additional precautions rather than a housekeeping choice (Public Health Ontario, infection prevention and control).
What do ASTM F1670 and ASTM F1671 actually measure?
Both are penetration tests run on the fabric, not on a finished garment. That distinction matters because a material can pass and a gown can still fail at a seam.
ASTM F1670 challenges the material with synthetic blood under hydrostatic pressure (ASTM F1670). It answers a physical question: does a liquid with blood-like surface tension push through the fabric at the pressure applied? The result is a pass or fail at a stated pressure, which is why a supplier quoting "passes F1670" without the pressure is quoting half a sentence.
ASTM F1671 goes further and uses a bacteriophage, Phi-X174, as a surrogate for bloodborne viruses (ASTM F1671). The phage is small enough to behave like a viral particle, so the test asks whether the material blocks a virus-sized challenge under pressure, not merely whether it holds back red fluid. This is the test referenced when a gown is described as bloodborne pathogen resistant, and it is the test that a Level 4 gown has to pass in its critical zone.
The pressure element is worth dwelling on. An isolation gown worn at arm's length during a dressing change sees nothing like the pressure of a soaked lap during an arterial bleed. The tests are deliberately harsher than the average shift because the consequence of the rare shift is high.
What does EN 13795 add for surgical gowns and drapes?
EN 13795 is the European standard family for surgical clothing and drapes. Where the ASTM methods answer one question each, EN 13795 sets a basket of performance requirements split between two product areas: the critical area, which is the part of the gown or drape most likely to be contaminated, and the less critical area. It then sets two performance levels, standard and high, and applies tests for tensile strength when dry and wet, tear resistance, burst strength, linting, liquid resistance and wet microbial penetration.
For a Canadian buyer the practical translation is plain: a gown that is EN 13795 compliant has been assessed for mechanical strength and lint release as well as barrier behaviour. That is relevant in an operating theatre where a gown can be gripped, tugged and soaked, and less relevant in a clinic where a Level 1 gown is worn to keep a sleeve clean during a routine exam.
| Test or standard | What it challenges | How the result is reported | Where it is usually cited |
|---|---|---|---|
| ASTM F1670 | Synthetic blood under hydrostatic pressure | Pass or fail at a stated pressure | Blood and fluid resistance claims |
| ASTM F1671 | Bacteriophage Phi-X174, a virus surrogate, under pressure | Pass or fail | Bloodborne pathogen resistance; Level 4 critical zone |
| EN 13795 | Tensile, tear, burst, lint, liquid and wet microbial penetration across critical and less critical areas | Standard or high performance | Surgical gowns and drapes sold in or into the EU |
| AAMI PB70 | Water impact and hydrostatic resistance, with F1671 at Level 4 | Level 1 to 4, judged by the critical zone | North American gown labelling |
How do the AAMI PB70 levels relate to these tests?
AAMI PB70 is the North American labelling convention, and it is the number a buyer should look for first because it converts several tests into one ladder. The level is determined by the critical zone, which is normally the front panel and the sleeves.
| PB70 level | Water impact resistance | Hydrostatic resistance | Viral penetration | Typical setting |
|---|---|---|---|---|
| Level 1 | Minimal, suitable for light splash | Not required | Not required | Exams, vitals, low-fluid contact |
| Level 2 | Low, short-duration splash | Required at a modest threshold | Not required | Blood draws, minor procedures, specimen handling |
| Level 3 | Moderate, longer fluid contact | Required at a higher threshold | Not required | Longer procedures, higher fluid volume |
| Level 4 | Highest | Required | Must pass ASTM F1671 | Fluid-intensive procedures where pathogen exposure is a named risk |
Two traps live inside that table. The first is that a Level 1 gown is a real product with a real job. It is not a failed Level 4 gown. Buying Level 4 everywhere is one of the fastest ways to inflate a PPE budget, and it changes nothing about how a routine blood draw is performed.
The second trap is that the level describes the criterion zone, not every square centimetre. Seams, ties and cuffs are constructed, not poured, and construction is where a light material can be defeated. A gown that passes F1671 as a sheet can still wick at the sleeve seam if the seam is not sealed or reinforced. Ask about the critical zone definition, not only the level number.
How do you verify a gown claim before you buy?
Manufacturers' test reports travel with the product, and they are worth requesting rather than assuming. A usable report names the test method with its year designation, the laboratory, the specific material or construction tested, and the pressure or level outcome. A report that says only that the material was "tested" is not evidence of anything.
Regulatory context is also worth knowing. In Canada, medical devices including many PPE items sit under the Medical Devices Regulations administered as part of the federal framework, which is why importers and distributors carry establishment licensing (Health Canada, medical devices). Supplier paperwork is a legitimate question to ask before a first order, not an insult, and public health units expect facilities to be able to answer it.
For facilities with a written exposure control plan, the workplace side matters too. CCOHS maintains plain-language material on biological hazards that is useful when writing the gown section of a plan (CCOHS, biological hazards), and the World Health Organization's infection prevention guidance remains the neutral reference when a committee wants a source that is not a vendor (WHO, infection prevention and control).
How many gowns does a clinic actually get through?
A ten-exam-room clinic using one Level 1 gown per encounter, ten encounters per room per day, at five days a week, is looking at roughly 2,500 gowns a month before procedures are counted. LTC homes run lower per bed but consume continuously because gowns are used for contact precautions and personal care.
That arithmetic matters because gown choice compounds. Moving every routine encounter from Level 4 to Level 1, and reserving higher levels for procedures that actually generate fluid, typically changes the annual line item more than any single negotiation over unit price. The clinical rule to hold onto is that the level must match the task, and the task must be written down.
CliniEco stocks Level 1 non-woven fluid-resistant isolation gowns for routine encounters and an SMS 40 gsm Level 2 gown for procedures with splash risk. The SMS gown's meltblown layer is what buys the higher water impact result, and the 40 gsm weight is the trade-off between barrier and heat load that most clinical staff notice by mid-shift. Facilities working toward a lower-plastic footprint can look at the PLA biodegradable Level 1 gown, which carries the same Level 1 fluid resistance expectation.
Buying for a facility rather than a single practice? Request a B2B quote and we will price your volume with Canadian warehouse delivery. Where a facility also reprocesses instruments inside the same infection-control program, the biological indicator 5-pack trial is a low-commitment way to verify the autoclave cycle behind it.
Related reading
- How to Verify an Isolation Gown Meets AAMI PB70 Level 4 — what a Level 4 claim should come with.
- Isolation Gown Standards: ASTM F2407 and AAMI PB70 Compared for Buyers — how the specification standard and the labelling standard fit together.
- Disposable Isolation Gowns: When Level 1 Is Enough — task-by-task selection for clinics and care homes.
- SMS Gown Material: Meltblown Filtration and the 40 gsm Trade-Off — the material behind Level 2.
- free Ontario sterilization compliance log
Ordering in volume or comparing suppliers? Start from the clinic supply range or send a wholesale inquiry with your monthly gown and glove volumes and we will quote against them.
Frequently Asked Questions
Does a Level 1 isolation gown protect against blood?
Level 1 is built for light splash and short contact, not for procedures that generate fluid. It has no F1671 requirement and no hydrostatic threshold to meet. For a blood draw with a splash risk, a Level 2 gown is the practical floor; for fluid-intensive work, Level 4 is the level that requires the viral penetration test.
What is the difference between ASTM F1670 and F1671?
F1670 uses synthetic blood to test liquid penetration under pressure. F1671 uses a bacteriophage as a virus surrogate, so it tests whether a pathogen-sized challenge can get through. A material can pass F1670 and fail F1671; the reverse does not normally happen because the viral challenge is the harder one.
Is EN 13795 the same as AAMI PB70?
No. EN 13795 is a European standard family that sets mechanical and barrier performance for surgical gowns and drapes across critical and less critical areas, with standard and high performance levels. AAMI PB70 is a North American labelling ladder with four levels driven mainly by water impact and hydrostatic resistance, plus F1671 at Level 4.
Do I need Level 4 gowns in a dental office?
For the overwhelming majority of dental procedures, no. Level 1 or Level 2 matches the fluid volumes involved. Level 4 belongs to procedures where substantial fluid or blood exposure is expected. A dental office that buys Level 4 for every appointment is paying a premium for a protection level the appointment does not require.
Are gown test reports supposed to come with the shipment?
They should be available on request, and a supplier who cannot produce them for a barrier claim is a supplier to be cautious about. Ask for the method, the year designation such as F1671, the testing laboratory and the specific material or construction tested. Keep the report with the product's lot information so the paperwork still lines up a year later.
What is the critical zone on a gown?
It is the part of the garment where contamination is most likely and where the performance level is judged, generally the front panel and the sleeves. It is the reason two gowns can carry the same level while behaving differently at the seams and cuffs, and the reason a specification question about seam construction is a fair one.
Can a reusable gown be used instead of a disposable one?
Reusable gowns exist and can meet barrier requirements when laundering, inspection and retirement rules are followed properly. The trade-off is the laundry cycle: a reusable gown's protection depends on the wash process, the number of cycles and the inspection regime. Facilities that cannot document those steps usually get more consistent results from single-use gowns.
How should gowns be stored before use?
In a closed cabinet or cupboard, away from sinks, sterilizer exhaust and sunlight, in the original carton so the lot number and level marking stay legible. Rotate stock first in, first out, and keep the test report with the carton rather than in a separate binder that nobody opens during an audit.
CliniEco Medical is a licensed medical device establishment (MDEL #35334).
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