Gown purchasing goes wrong in two directions. Buy below the level the task needs and infection prevention rejects the case. Buy above it and you pay Level 3 prices for a task that a Level 1 gown covers, which at hospital volumes is real money.
The ANSI/AAMI PB70 standard exists to stop both mistakes. It classifies protective apparel by liquid barrier performance, and the FDA has recognized it since 2004. Here is what the levels mean, what they are tested against, and how to turn them into a spec your supplier can quote without a phone call.
The four levels
| Level | Barrier | Typical use | Test methods |
|---|---|---|---|
| 1 | Minimal | Basic care, standard isolation, cover gowns for visitors | AATCC 42 (water impact) |
| 2 | Low | Blood draw, suturing, ICU, pathology lab | AATCC 42 and AATCC 127 (hydrostatic pressure) |
| 3 | Moderate | Arterial blood draw, IV insertion, ER, trauma | AATCC 42 and AATCC 127 at higher thresholds |
| 4 | Highest | Long, fluid-intensive procedures, surgery, when pathogen resistance is required | ASTM F1670 (synthetic blood) and ASTM F1671 (viral penetration) |
Only Level 4 is tested for viral penetration. Levels 1 through 3 provide increasing resistance to liquids; they are not tested as barriers to bloodborne pathogens. That single fact settles most spec disputes.
Surgical versus non-surgical
The level tells you how much fluid the fabric stops. A second distinction tells you where the gown may be used.
- Surgical gowns are FDA Class II devices cleared through 510(k). Their barrier level applies to the critical zones (the front and the sleeves), and the seams are part of the test.
- Non-surgical gowns, which include most isolation gowns, are FDA Class I and exempt from premarket review. They are intended for minimal-to-low risk situations, and the barrier claim applies to the whole garment rather than defined critical zones.
A Level 3 isolation gown and a Level 3 surgical gown are not the same product. The surgical gown has cleared a regulatory bar the isolation gown has not. Do not accept one as a substitute for the other on a surgical requisition.
How to write the spec
A gown line on an RFQ should carry six things:
- Gown type: surgical or non-surgical (isolation).
- AAMI PB70 level: 1, 2, 3, or 4, and the phrase "manufacturer-labeled" so the claim is on the box, not in an email.
- Sterile or non-sterile.
- Material: polypropylene, PP/PE laminate, SMS, or reusable polyester. This drives comfort, heat, and cost more than the level does.
- Closure and sizing: neck (tie, hook-and-loop, over-the-head), waist ties, thumb loops or knit cuffs, and the size run (universal, or S through 2XL).
- Packaging: gowns per bag and per case, and whether the case is a mixed size run.
Ask for the manufacturer's test summary with the quote. A legitimate supplier can send the AAMI level documentation the same day.
Where buyers overspend
Most inpatient units run Level 1 or Level 2 isolation gowns for routine contact precautions. Reserve Level 3 for ER, trauma, and procedures with moderate fluid exposure. Level 4 belongs in surgery and in any setting where the risk assessment calls for pathogen resistance. A facility that standardizes on Level 3 "to be safe" for every contact isolation room is paying for barrier performance it never uses.
Reusable gowns deserve a real comparison. A laundered polyester Level 2 gown can cost less per use than disposable at high volumes, if your laundry partner tracks wash cycles and the level is re-verified.
Where buyers underspend
Two places. Visitor and cover gowns bought at Level 1 that end up on staff during a fluid-heavy procedure. And "AAMI Level" claims on import listings with no test documentation. If the box does not state the level and the manufacturer cannot produce the test report, treat it as unrated.
Stocking through a shortage
Gowns were among the first PPE lines to hit allocation in 2020 and they remain sensitive to import disruption. Standardize on two manufacturers per level, keep both on the approved list, and put your highest-volume level on a standing order. Keystone stocks isolation and surgical gowns in Edina, quotes AAMI-labeled product with documentation, and can hold a buffer for health systems under an open purchase order.
Browse gowns and protective apparel or request a gown quote by level and size run.
Sources
- CDC NIOSH, Protective Clothing Standards and Specifications: https://www.cdc.gov/niosh/healthcare/protective-clothing/standards.html
- FDA, Medical Gowns: https://www.fda.gov/medical-devices/personal-protective-equipment-infection-control/medical-gowns
- Medline, "Medical gown options: AAMI standards applied to more PPE gowns": https://www.medline.com/strategies/infection-prevention/protective-medical-gown-aami-ratings/