Understanding Barrier-Level Protection of Medical Gowns

Exposure to the pathogenic microorganisms harbored in blood, body fluids and other potentially infectious material (OPIM) can lead to occupationally acquired infections (OAIs) in healthcare workers (HCWs). That’s why it’s critical that healthcare providers don key pieces of personal protective equipment (PPE) and understand the levels of barrier protection these PPE items can afford them in patient-care and surgical situations.

The Association for the Advancement of Medical Instrumentation (AAMI) standard, “Liquid Barrier Performance and Classification of Protective Apparel and Drapes Intended for Use in Health Care Facilities” (ANSI/AAMI PB70), has served as the gold standard for the manufacturing of medical gowns’ barrier performance, which is key in preventing fluid and microbial strikethrough – a contributor to OAIs. The AAMI standard addressed the issue raised by the Occupational Safety and Health Administration (OSHA)’s Standard on Occupational Exposure to Bloodborne Pathogens, which mandated that the employer provide the HCW with protective apparel that is commensurate with the task and degree of exposure anticipated. What was needed was a method by which to assess a gown’s protective properties and ensure that it was suitable for the clinical task at hand; the AAMI standard introduced a classification system that guided manufacturers in the testing and labeling of the barrier performance of their products. In addition to strikethrough, the standard addresses parameters for flammability resistance and linting, which can serve as a carriage vehicle for microbial particles.

At the heart of this AAMI standard are the four levels of barrier protection, ranging from level one, which is the lowest level of protection, to level four, which is the highest level. Utilizing these classification levels, manufacturers are able to label their products according to the level of protection their product provides, and HCWs can more easily select the appropriate barrier they need. All gowns and surgical drapes are subject to this classification system.