What's the Difference Between Surgical and Isolation Gowns?


PPE Essentials: Gowns

What reps need to know about different types, requirements, claims and standards of gowns used in medical settings.

By William Bagnasco, ASQ CQA, PMI CAPM, CLSSGB, Director of Quality and Regulatory Affairs, DUKAL Corporation

As the novel coronavirus has spread across the globe, Personal Protective Equipment, also known as PPE, has become the hottest topic in the medical device industry. Along with the increased demand for PPE, came an influx of new suppliers to the market. As new suppliers emerged, so did the questions related to the different types of PPE and various levels of protection that they offer.

Since the onset of the virus in early 2020, the industry has scrambled to secure appropriate product to meet the needs of healthcare workers required to protect themselves and patients from the spread of infection. This article will focus on the different types of gowns, the requirements and claims associated with level rated gowns, and draw attention to the inconstancies between AAMI’s standards and those of the FDA.

> The definitions used in the ANSI/AAMI PB70 standard are inconsistent with those used by the FDA, which has caused confusion in the industry.

Types and standards

The American National Standards Institute (ANSI) and the Association of the Advancement of Medical Instrumentation (AAMI): ANSI/ AAMI PB70 describes liquid barrier performance and classification of protective apparel and drapes intended for use in healthcare facilities. In 2004, the FDA recognized ANSI/AAMI PB70 as the consensus standard. AAMI PB70 defines an “isolation gown” as an “item of protective apparel used to protect healthcare personnel and patients from the transfer of microorganisms and body fluids in patient isolation situations,” and “surgical gowns” as “devices that are intended to be worn by operating room personnel during surgical procedures to protect both the surgical patient and the operating room personnel from the transfer of microorganisms, body fluids, and particulate material.” (21 CFR 878.4040)1

The main difference between an isolation gown and a surgical gown are the critical zones identified for testing and that the back of a surgical gown may be nonprotective. Whereas the back of a level rated isolation gown must offer full back coverage and have a barrier performance of at least a Level 1.

The ANSI/AAMI PB70 standard has 4 levels of fluid barrier protection, with Level 1 being the lowest level of protection and Level 4 being the highest. The following is a table showing the different levels of rated gowns, test methods, and the anticipated fluid exposure for each performance level.

According to the FDA, both surgical gowns and isolation gowns are considered surgical apparel and are covered under the requirements of 21 CFR 878.4040. Gowns that are not intended for use in a surgical setting are Class I devices. They are intended to protect the wearer from the transfer of microorganisms and body fluids in low risk patient isolation situations. This includes both Level 1 & 2 isolation gowns, as well as non-rated isolation gowns. The agency identifies gowns that are intended to be used in surgery as Class II devices which require a pre-market notification. A pre-market notification, also known as a 510k submission, ensures that a device meets specific performance standards, labeling requirements and its intended use by demonstrating substantial equivalence to another device which has been shown to be safe and effective.2 The definitions used in the ANSI/AAMI PB70 standard are inconsistent with those used by the FDA, which has caused confusion in the industry. Unlike AAMI, the FDA considers both the level of barrier protection and the terminology used in the marketing and labeling of the device. In 2015, the FDA issued a guidance document clarifying their approach.

The FDA considers gowns with moderate to high barrier protection (Levels 3 & 4) to be a higher-risk device than gowns that claim minimal or low levels of fluid protection (Levels 1 & 2, and non-rated gowns). The FDA automatically considers a gown to be a “surgical gown” or “surgical isolation gown” when it has a statement relating to moderate or high-level barrier protection. This means that if a gown is labeled as an AAMI Level 3 or 4, it’s considered a “surgical gown” and is subject to the requirements of premarket notification. This contradicts the ANSI/AAMI PB70 standard that states that surgical gowns can be classified as Level 1-4.3

What does this all mean?

To simplify it, a “surgical gown” that is marketed in the United States cannot claim to be AAMI Level 1 or 2 because using the word “surgical” on the label or in any marketing material implies that the gown is intended for use in a surgical setting. Any gown labeled or marketed with the words “surgical”, “surgical gown” or “surgical isolation gown” is automatically elevated to a Class 2 device, requires a premarket notification and should be identified as either AAMI Level 3 or 4. On the other hand, isolation gowns can be rated AAMI Level 1-4 or they can be non-rated. There are non-rated isolations gowns that offer fluid protection which don’t carry a level rating due to the construction features of the gowns, such as having an open back design and/or sewn seams. Any isolation gown that carries an AAMI Level 3 or 4 designation would be considered a high-risk device and would require a premarket notification.

Now that we have a better understanding of the different types of gowns and the differences between FDA regulations and the ANSI/AAMI standard, we can look at what should be reviewed with regards to claims, prior to purchasing a gown.

> Level 1 Isolation Gown: The manufacturer should provide test reports, according to AATCC 42, showing that all critical areas of the gown were tested for fluid resistance and that all test requirements were met. Level 1 gowns offer protection against minimal fluid levels.

> Level 2 Isolation Gown: The manufacturer should provide tests reports, according to AATCC 42 & AATCC 127, showing that all critical areas of the gown were tested for fluid resistance and that all test requirements were met. Level 2 gowns offer protection against low fluid levels.

> Level 3 & 4 Gown (Surgical and Isolation): A copy of the 510k summary should be reviewed to ensure FDA clearance. Level 3 & 4 gowns offer protection against moderate and high fluid levels respectively.

An important thing to remember is that all claims that are made with regards to fluid protection should be made on the final, finished gown including the materials, seams and points of attachment. There are gowns on the market that claim that the “material” is fluid resistant. This is an important factor to consider when trying to select the appropriate gown based on its barrier properties. Having a better understanding of the different types of gowns, the various regulations/standards that cover these gowns and the proper supporting documentation will allow you to select the appropriate gown and ensure that the gown does in fact meet the intended use and labeling claims

1 Sections 3.13 and 3.31 of the ANSI/AAMI PB 70:2012 (citing 21 CFR 878.4040).
2 https://www.fda.gov/medical-devices/personal-protective-equipment-infection-control/medical-gowns#g4
3 Guidance document on Premarket Notification Requirements Concerning Gowns Intended for Use in Health Care Settings

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