Liquid Repellency and Surgical Fabric Barrier Properties

Abstract

Those who are responsible for controlling the surgical environment require a technically sound, practical, valid, and consistent means of evaluating the barrier properties of surgical drapes and apparel. While many laboratories have, by necessity, agreed upon a limited number of test procedures to evaluate the liquid penetration resistance or repellency of a barrier material, there is no uniform code or guideline that defines the preferred method or methods of evaluation. Assuming wet bacterial transmission through a barrier material is related to the liquid penetration resistance of that material, the following paper attempts to outline the physicochemical basis of repellency in terms of a word equation, define the terminology and relevance to surgical barriers, and suggest the optimum choices of tests from among those in common usage including the group that had been under consideration by the Association for the Advancement of Medical Instrumentation (AAMI) Aseptic Barrier Materials Committee. Because the liquid penetration resistance of a barrier material is a function of both permeability and surface wettability, comprehensive evaluation must include tests for both properties. No single test has been shown to do this reproducibly. Two tests, used by a number of industrial labs, are recommended because, while each test reflects predominantly the degree of either porosity or wetting, together they have been shown to yield information on both properties reliably with results that can be reproduced. These two tests, the fixed liquid pressure test and the dynamic impact test, are simple, non-destructive, and require little special equipment, so they can be performed relatively rapidly on both linens and single-use non-wovens.