Preliminary evaluation of filtration efficiency and differential pressure astm f3502 testing methods of non-medical masks using a face filtration mount

Research surrounding the mandated use of non-medical fabric masks is inconsistent and often confusing when compared to the standard N95 A recently published standard from ASTM International and the Centers for Disease Control and Prevention attempts to normalize evaluation procedures The purpose of this study is to conduct a preliminary evaluation of the new methods for testing filtration efficiency of masks outlined by ASTM International F3502, where results can be directly compared to standards outlined for non-medical fabric masks Eleven consumer non-medical fabric masks were tested for filtration efficiency and airflow resistance using a face filtration mount in accordance with the newly released ASTM International standard for facial barriers The mean FE% (SD) ranged from 0 46% (0 44) to 11 80% (2 76) with the 3-layer athletic mesh having the highest performance and the highest deviations All the masks tested following the procedure failed to meet to minimum FE of 20%;however all masks performed below the minimum upper limits for airflow resistance Using a non-medical fabric masks as the sole mitigation strategy may not be as effective, as previously reported With efforts to standardize and regulate the non-medical fabric mask market, this study demonstrates a variety of currently available consumer mask products do not meet the minimum standards nor are these remotely close to the standards of surgical or N95 masks © 2021 by the authors Licensee MDPI, Basel, Switzerland