Gowns (surgical, isolation, or low-risk `cover’) are the second most common form of barrier protection used by Healthcare workers, exceeded only by disposable gloves. Although they come in many styles and design, the FDA recognizes four main types (see FDA - Medical Gowns)
- Level 1: Minimal risk, to be use used, for example, during basic care, standard isolation, cover gown for visitors, or in a standard medical unit
- Level 2: Low risk, to be use used, for example, during blood draw, suturing, in the Intensive Care Unit (ICU), or a pathology lab
- Level 3: Moderate risk, to be use used, for example, during arterial blood draw, inserting an Intravenous (IV) line, in the Emergency Room, or for trauma cases
- Level 4: High risk, to be use used, for example, during long, fluid intense procedures, surgery, when pathogen resistance is needed or infectious diseases are suspected (non-airborne)
The most stringent standards apply for isolation gowns, which the FDA describes as:
Surgical Isolation Gowns
Surgical isolation gowns are used when there is a medium to high risk of contamination and a need for larger critical zones than traditional surgical gowns. Surgical isolation gowns, like surgical gowns, are regulated by the FDA as a Class II medical device that requires a 510(k) premarket notification. As referenced in Figure 2, all areas of the surgical isolation gown except bindings, cuffs, and hems are considered critical zones of protection and must meet the highest liquid barrier protection level for which the gown is rated. All seams must have the same liquid barrier protection as the rest of the gown. Additionally, the fabric of the surgical isolation gown should cover as much of the body as is appropriate for the intended use.
Gowns must meet exacting standards for Tensile Strength ( ASTM D5034, ASTM D1682), Tear resistance (ASTM D5587(woven), ASTM D5587 (nonwoven), ASTM D1424), Seam Strength: ASTM D751 (stretch woven or knit), Lint Generation (ISO 9073 Part 10), Water vapor transmission (breathability) ASTM F1868 Part B, ASTM D6701 (nonwoven), ASTM D737-75, and lastly liquid barrier performance (ANSI/AAMI PB70:2003).
With the recent importations of Ebola and MERS into the United States, along with the more commonly encountered blood borne pathogens like HIV, HVC & HVB, there has been a renewed interest in the proper use, and design, of PPEs (Personal Protective Equipment) like gloves, gowns, and masks (N95 & surgical).
Today, the NIOSH Science Blog carries a report on recent tests conducted on 22 different isolation gowns (from 6 manufacturers). When tested for liquid barrier performance by the National Personal Protective Technology Laboratory (NPPTL), they found that 7 gowns (31.8%) did not meet ANSI/AAMI PB70:2003 standards.
Additionally, the found that `seams and ties on some gowns were not constructed adequately to keep liquids and/or viruses from penetrating’ on some of these protective garments.
I’ve only included some excerpts, follow the link below to read it in its entirety.
July 22nd, 2015 8:45 am ET - Selcen Kilinc-Balci, PhD, MBA and Maryann D’Alessandro, PhD
Recent research performed at the NIOSH National Personal Protective Technology Laboratory (NPPTL), with support from Nelson Laboratories, suggests that some isolation gowns do not meet the performance standards established by the American National Standards Institute (ANSI)/Association for the Advancement of Medical Instrumentation (AAMI).
Our research revealed that seven of the 22 tested disposable models did not meet ANSI/AAMI PB70 liquid barrier performance standard for protective apparel and drapes. When tested for fabric’s resistance to tearing and breaking and seam resistance to breaking, the 22 models showed a wide range of performance. While some gowns met the performance requirements of the standard, seams and ties on some gowns were not constructed adequately to keep liquids and/or viruses from penetrating at these particular points of the isolation gowns.
NIOSH is working with manufacturers to identify issues and determine necessary corrective action to assure that products on the market are providing the expected level of protection to the end user. NIOSH continues to work with the ASTM committee to identify other research gaps where the institute’s expertise can lead the nation to identify appropriate PPE performance requirements for worker safety.