Overview

According to the Centers for Disease Control and Prevention (CDC), health care workers have the potential for exposure to biological fluids that are capable of transmitting diseases caused by viruses such as hepatitis B, hepatitis C, human immunodeficiency virus, Ebola and others. The design of protective clothing (e.g., isolation gowns, coveralls and surgical gowns) shields health care workers and patients from harmful microorganisms transferred by blood and body fluids and should be worn when a threat of exposure exists.

There a variety of protective products available, so here are factors and details to help guide your selections.

Gown types

Figure 1. Personal protective equipment gown types

Type Example Coverage
Isolation gowns Isolation gown Isolation gowns do not provide continuous whole-body protection (e.g., possible openings in the back, coverage to the mid-calf only)
Coveralls Coveralls Coveralls typically provide 360-degree protection because they are designed to cover the whole body, including back and lower legs and sometimes head and feet as well
Surgical gowns Surgical gown Surgical gowns do not provide continuous whole-body protection (e.g., possible openings in the back, coverage to the mid-calf only)

Gown selection factors

There are three primary factors that influence personal protective equipment (PPE) gown selection:

  1. Purpose
    Isolation gowns are generally the preferred PPE clothing. Choose isolation gowns for instances you anticipate arm contamination. Gowns should fit comfortably over the body, cover the torso, and have long sleeves that fit snuggly around the wrists.
  2. Materials
    Gowns are made primarily from cotton or a spun synthetic material. Each of these materials are available in varying degrees of fluid resistance. If fluid penetration is a concern, then choose a fluid resistance gown.
  3. Risk
    Choose clean or sterile gowns, depending on the particular risk factors involved. Use clean gowns generally for isolation purposes, while sterile gowns are only necessary when performing invasive procedures, such as inserting a central line. In this case, a sterile gown would protect both the patient and the health care worker.

It is important to understand the critical, primary protection zones of a gown when making a selection for a particular patient care scenario. The illustrations below indicate critical areas of both surgical and nonsurgical gowns.

Figure 2. Critical primary protection zone for surgical gowns

Surgical gown

  • The entire front of the gown material (areas A, B and C) is required to have a barrier performance of at least level 1. See table 1.
  • The critical zone comprises at least areas A and B.
  • The back of the surgical gown (area D) may be nonprotective material.

Figure 3. Critical zones for surgical isolation and nonsurgical gowns

Surgical isolation gown

Standards and performance requirements

Consensus standards for testing gown performance

The rating for isolation and surgical gowns is based on their ability to act as a barrier to liquids or liquid-borne pathogens. The Food and Drug Administration (FDA) recognized standard for gown rating was created by two organizations: the American National Standards Institute (ANSI) and the Association for the Advancement of Medical Instrumentation (AAMI).

ANSI is a private nonprofit organization that oversees the development of voluntary consensus standards for products, services, processes, systems and personnel in the United States. AAMI is an organization for advancing the development, and safe and effective use of medical technology. The FDA recognized standard from ANSI/AAMI is PB70:2012 and is known as the liquid barrier performance and classification of protective apparel and drapes intended for use in health care facilities.

Table 1. Defining four protective material levels

Level Description Applicability
Level 1
  • Use for minimal-risk situations
  • Provides a slight barrier to small amounts of fluid penetration
  • Single test of water impacting the surface of the gown material is conducted to assess barrier protection performance
Blood draw from a vein, suturing, intensive care unit, pathology lab
Level 2
  • Use in low-risk situations
  • Provides a barrier to larger amounts of fluid penetration through splatter and some fluid exposure through soaking
  • Two tests are conducted to assess barrier protection performance:
    • Water impacting the surface of the gown material
    • Pressurizing the material
Blood draw from a vein, suturing, intensive care unit, pathology lab
Level 3
  • Use in moderate-risk situations
  • Provides a barrier to larger amounts of fluid penetration through splatter and more fluid exposure through soaking than level 2
  • Two tests are conducted to assess barrier protection performance:
    • Water impacting the surface of the gown material
    • Pressurizing the material
Arterial blood draw, inserting an I.V., emergency room care, trauma care
Level 4
  • Use in high-risk situations
  • Prevents all fluid penetration for up to 1 hour
  • May prevent virus penetration for up to 1 hour
  • In addition to the other tests conducted under levels 1-3, barrier level performance is tested with a simulated blood containing a virus. If no virus is found at the end of the test, the gown passes.
Pathogen resistance, infectious diseases (nonairborne), large amounts of fluid exposure over long periods

The FDA requires that surgical gowns get additional testing for tear resistance, seam strength, lint generation, evaporative resistance and water vapor transmission. The standard recognized by the FDA for this testing (ASTM F2407) was created by ASTM International.

ASTM International (formerly known as The American Society for Testing and Materials) is an international standards organization that develops and publishes voluntary consensus technical standards for a wide range of materials, products, systems and services.

Table 2. Summary of ASTM standards the FDA recognizes

Test Standard(s)
Tensile strength ASTM D5034
Tear resistance ASTM D5587
ASTM D1424
Seam strength ASTM D751
Lint generation ISO 9073 part 10
Water vapor transmission (breathability) ASTM F1868 part B
ASTM D6701
ASTM D737

Covid-19 pandemic relevance

In response to the COVID-19 pandemic, on May 22, 2020, the FDA authorized emergency use of protective gowns and other apparel through the issuance of an Emergency Use Authorization (EUA) document in order to help address insufficient supply.

The FDA is allowing health care personnel to use the following otherwise-unapproved items, providing there is “no adequate, approved and available alternative” during the COVID-19 public health emergency:

  • Conductive shoes and shoe covers
  • Operating room shoes
  • Surgical apparel accessories
  • Nonsurgical isolation gowns
  • Operating room shoe covers
  • Surgical helmets
  • Surgical caps

These gowns and other apparel are deemed acceptable under the EUA when intended for use by health care personnel in health care settings, and in accordance with CDC recommendations to protect personnel and patients from the transfer of SARS-CoV-2 in low- or minimal-risk-level situations.

Criteria for issuance of the authorization

  1. The virus that causes COVID-19, a serious or life-threatening disease, can cause other conditions, including severe respiratory illness, to humans infected by this virus
  2. Based on the totality of scientific evidence available to FDA, it is reasonable to believe that the authorized gowns and other apparel worn by health care providers may be effective at preventing the transfer of microorganisms, bodily fluids, and particulate material in low- or minimal-risk situations by providing minimal-to-low barrier protection to health care personnel and patients to prevent the spread of COVID-19
  3. There is no adequate, approved and available alternative to the emergency use of these gown or other apparel

Capacity strategies

The CDC is providing options and strategies for optimizing the supply of isolation gowns.

These strategies are divided into three general strata with the intention to prioritize measures to conserve isolation gown supplies along the continuum of care:

Conventional capacity

  • Use isolation gown alternatives that offer equivalent or higher protection

Contingency capacity

  • Shift gown use to cloth isolation gowns
  • Consider the use of coveralls
  • Use expired gowns beyond the manufacturer-designated shelf life
  • Use gowns or coveralls that conform to international standards

Crisis capacity

  • Cancel all elective and nonurgent procedures and appointments for which health care providers typically use a gown
  • Extend use of isolation gowns
  • Re-use of cloth isolation gowns
  • Prioritize gown type selection per procedure type

Visit the COVID-19 Resources for more information.