Letter to Editor: Quantitative Fit Test of Double Layer Surgical Masks

Abstract

We presented our findings on quantitative fit factors of various respirators and masks and emphasized on both quality of materials and sealing or fitness of respirators and masks [REF1].  When the second epidemic of SARS-CoV-2 emerged in Thailand in late 2020, a concern was raised on shortage of personal protective equipment (PPE) supply, in particular N95 respirators and high performance face masks.  A related question was also raised whether using double layers of surgical masks would improve performance adequately.  We, therefore, conducted another quantitative fit factor assessment by Porta Count model 8048, TSI Incorporated, Minnesota, USA [REF 2], following OSHA (Occupational Safety and Health Administration) protocols [REF 3] to assess fit factors of double layers of surgical masks, with single sealing and double sealing in comparison with single layer with single sealing with micropore tape.  Here are the results.