Surgical and Isolation Gown Standards: EN 13795 and ANSI/AAMI PB70 Levels Explained

Short answer: two standards dominate gown specifications. ANSI/AAMI PB70 grades liquid barrier performance in four levels, from Level 1 (minimal) to Level 4 (stops blood and a virus surrogate under pressure), and is the scheme the US FDA uses to describe gown protection. EN 13795-1 grades surgical gowns and drapes as standard performance or high performance using microbial, cleanliness, liquid and strength tests, and is the harmonised European standard under the Medical Device Regulation. A tender should name the standard, the level or class, and the zones of the gown that must meet it.

ANSI/AAMI PB70: four liquid barrier levels

The current edition is ANSI/AAMI PB70:2022, released by AAMI in January 2023. The previous edition covered surgical gowns, surgical drapes and isolation gowns; the 2022 edition adds extended-coverage surgical gowns, non-surgical protective gowns such as procedure and decontamination gowns, hoods and togas, and aprons, shoe covers and sleeves, and requires labelling of the protected area (full coverage, non-protective back or open back). Gloves, masks and goggles are outside its scope.

The levels, as summarised by CDC/NIOSH:

Level	Test	Requirement	FDA example uses
1	AATCC 42 water impact penetration	≤ 4.5 g	Basic care, standard isolation
2	AATCC 42 impact; AATCC 127 hydrostatic pressure	≤ 1.0 g; ≥ 20 cm	Blood draw, suturing, ICU, pathology lab
3	AATCC 42 impact; AATCC 127 hydrostatic pressure	≤ 1.0 g; ≥ 50 cm	Arterial blood draw, IV insertion, ER, trauma
4	ASTM F1671 viral penetration (gowns); ASTM F1670 synthetic blood (drapes)	No penetration at 2 psi (13.8 kPa)	Long, fluid-intense procedures, surgery

Two points are easy to miss. First, Levels 1 to 3 use water as the only challenge, and CDC/NIOSH states that gowns at these levels cannot be considered impermeable. Second, Level 4 is pass/fail at a single pressure, so a “Level 4” claim tells you the critical zone stopped a viral surrogate at 13.8 kPa in the test, not that the gown is impervious in every condition.

For non-sterile isolation gowns, ASTM F3352 is the companion specification and references the PB70 levels.

Critical zones and US classification

A level applies to the critical zones of the gown, not necessarily the whole garment. On its Medical Gowns page the FDA defines them:

• Surgical gown: the front of the body from the top of the shoulders to the knees, and the arms from the wrist cuff to above the elbow. The whole front must be at least Level 1; the back may be non-protective.
• Surgical isolation gown: every area except bindings, cuffs and hems is a critical zone and must meet the highest level the gown is rated for.

For a task-by-task comparison of the two gown types, see isolation gown vs surgical gown.

Classification follows the same split. Surgical gowns and surgical isolation gowns are Class II medical devices that need 510(k) premarket notification; non-surgical isolation gowns are Class I and exempt from premarket review (21 CFR 878.4040). Non-surgical, non-isolation gowns with moderate or high barrier claims are Class II, and those with minimal or low claims are Class I.

Quality varies in practice. In a NIOSH assessment of stockpiled PPE reported by AIHA in 2022, five of ten gown lots failed the PB70 hydrostatic requirement. Material choice matters too: a NIOSH-authored review notes that gowns offer varying resistance to blood and body fluids depending on the material. Testing the finished gown, including sleeve seams and tie attachments, is what makes a claim credible.

EN 13795-1: standard and high performance

EN 13795-1 sets requirements for surgical gowns and drapes. EN 13795-1:2025 replaced the 2019 edition (BSI lists BS EN 13795-1:2019 as withdrawn in February 2025), and the European Commission listed EN 13795-1:2025 as a harmonised standard under Regulation (EU) 2017/745 in Implementing Decision (EU) 2025/2078, which gives conforming products a presumption of conformity. DIN’s summary of the 2025 changes lists clarified test specifications and reporting, wet bursting specimen preparation to EN ISO 13938-1:2019, an expanded annex on environmental impact, and alignment with the MDR. Clean air suits are covered separately in EN 13795-2.

The standard distinguishes the critical product area (where there is a greater probability of transferring infective agents to or from the wound; for a gown, the front and sleeves) from the less critical product area, and sets two performance classes. The requirements for gowns in the 2019 edition, as published in MSF’s procurement catalogue, were:

Property	Test method	Standard performance	High performance
Microbial penetration, dry	EN ISO 22612	≤ 300 CFU (less critical area)	≤ 300 CFU (less critical area)
Microbial penetration, wet	EN ISO 22610	Barrier index ≥ 2.8 (critical area)	Barrier index 6.0 (critical area)
Microbial cleanliness	EN ISO 11737-1	≤ 300 CFU/100 cm²	≤ 300 CFU/100 cm²
Linting	EN ISO 9073-10	≤ 4.0 log10 lint count	≤ 4.0 log10 lint count
Liquid penetration	EN ISO 811	≥ 20 cm H₂O critical; ≥ 10 cm less critical	≥ 100 cm H₂O critical; ≥ 10 cm less critical
Bursting strength, dry and wet	EN ISO 13938-1	≥ 40 kPa (wet: critical area)	≥ 40 kPa (wet: critical area)
Tensile strength, dry and wet	EN 29073-3	≥ 20 N (wet: critical area)	≥ 20 N (wet: critical area)

The 2025 change list does not indicate new limits, but confirm the values against the current standard when you write a specification. The NHS Wales Surgical Materials Testing Laboratory lists the same set of test methods for surgical textiles, and test programmes should include weak points such as seams within the critical area.

How PB70 and EN 13795 differ

	ANSI/AAMI PB70:2022	EN 13795-1:2025
Grades	Levels 1 to 4	Standard and high performance
What is tested	Liquid barrier (water; blood and virus surrogate at Level 4)	Microbial penetration, cleanliness, linting, liquid penetration, strength
Zones	Critical zones defined by product type	Critical and less critical product areas
Regulatory link	Used by the US FDA to describe gown barrier levels	Harmonised under EU MDR 2017/745
Typical market	US and markets referencing FDA practice	EU and markets referencing CE marking

Neither maps exactly onto the other. A high-performance EN 13795 gown must reach 100 cm H₂O in the critical area under EN ISO 811, while PB70 Level 3 requires 50 cm under AATCC 127; the methods differ, so the numbers are not interchangeable. EN 13795 also has no viral-penetration test equivalent to PB70 Level 4. If a tender references one standard, ask for test evidence against that standard rather than a conversion.

Isolation gowns as PPE: EN 14126

In Europe, protective clothing against infective agents that is not a surgical gown is generally assessed as personal protective equipment under Regulation (EU) 2016/425, where harmful biological agents are a Category III risk. The usual standard is EN 14126, which uses ISO 16603 (synthetic blood), ISO 16604 (viral penetration, classes 1 to 6 up to 20 kPa), ISO 22610 (wet bacterial penetration), ISO 22611 (biological aerosols) and ISO 22612 (dry particles). CEN-CENELEC guidance is that a product marketed as both a medical device and PPE must meet the requirements of both regulations.

Writing a gown specification

1. State the standard and the level or class: for example “ANSI/AAMI PB70 Level 3, critical zones per FDA” or “EN 13795-1:2025 high performance”.
2. Define the coverage: surgical gown (front and sleeves) or surgical isolation gown (all areas except bindings, cuffs and hems).
3. Specify sterile or non-sterile, sterilisation method, sizes, and fabric type and weight as secondary information, not as a proxy for barrier level (our non-woven fabrics guide explains SMS, SMMS and GSM).
4. Require test reports for the finished gown from an accredited laboratory, covering seams in the critical zone.
5. For EU-referenced tenders, ask whether the gown is placed on the market as a medical device, PPE, or both.

Where WinHyCare’s gowns fit

Our range covers four constructions: the SMS surgical gown (SMS, SMMS, SMMMS or spunlace, 30 to 70 gsm, reinforced or standard, EO sterile or non-sterile), the PP non-woven isolation gown (16 to 50 gsm, breathable, for low-to-moderate splash risk), the PE-coated isolation gown (PP laminated with PE film to block liquid strike-through) and the CPE gown with thumb loops (fully waterproof film).

We do not assign a PB70 level or EN 13795 class to these gowns as a range, because barrier performance belongs to a tested design. Before you bid, ask for the documents we hold for the exact item and fabric weight; we will tell you what has been tested and what has not. Buyers in Saudi Arabia and the GCC can see how we ship and document orders on our GCC supply page, or browse all surgical and isolation gowns.