Abstract View
Filtration Efficiency of Respirators and Masks – How You Test Matters
TIM JOHNSON, Justin Koczak, Andrea Tiwari, TSI Incorporated
Abstract Number: 206
Working Group: The Role of Aerosol Science in the Understanding of the Spread and Control of COVID-19 and Other Infectious Diseases
Abstract
Recent global health developments have highlighted that the particulate filtration efficiency testing standards and procedures covering respirators, masks, and their media are often written in very general terms. These methods can rely on guidance from other organizations to provide the rest of the necessary details. Testing of surgical facemasks in the United States, for example, can require understanding requirements put forth by the ASTM, NIOSH, and the FDA, depending on the mask classification. This creates confusion for producers and testing organizations.
Moreover, in response to high demand, non-standard fabric and homemade masks are being produced in increasing volumes. A lack of clear testing guidance for this new class of masks has resulted in a wide variety of methods being used that give conflicting results, which compounds the problem. This trickles down to the end user, who may not have an accurate understanding of how well their mask or respirator is protecting them.
This presentation seeks to help clarify some of this confusion. Its objective is to provide members of the filtration and aerosol science communities with a basic understanding of the key factors at play in filtration testing. This will enable these scientists and engineers to better understand the methods and standards they may be required to test in accordance with; and to help them make better-informed decisions when deciding how to test and do research on masks and respirators that may fall outside the purview of officially-published guidance or requirements.
To this end, this presentation will address some key filtration fundamentals, selected testing methods, and the standards, the instrumentation that they depend on - aerosol generators and their resulting particle size distributions, different detector types, etc. - and how these factors can affect the test results.