Evaluation of Cloth Masks and Modified Procedure Masks as Personal Protective Equipment for the Public During the COVID-19 Pandemic
Importance: During the COVID-19 pandemic, the general public has been advised to wear masks or improvised face coverings to limit transmission of SARS-CoV2. However, there has been considerable confusion and disagreement regarding the degree to which masks protect the wearer from airborne particles. Objectives: To evaluate the fitted filtration efficiency (FFE) of a variety of consumer-grade and improvised facemasks, as well as several popular modifications of medical procedure masks. Design: Masks and face coverings were fitted on an adult male and FFE measurements (particle concentration behind the mask expressed as a percentage of ambient particle concentration) were collected during a series of repeated movements of the torso, head, and facial muscles as outlined by the OSHA Quantitative Fit Testing Protocol. Setting: Research laboratory Participants: Adult male volunteer Main Outcome(s) and Measure(s): The primary study outcome was to measure the FFE of common consumer-grade and improvised facemasks, as well as several popular modifications of medical procedure masks. Results: The FFE of consumer grade masks ranged from 79.0%±4.3% to 26.5%±10.5%, with the Easy Masks™ EDEN nylon mask having the highest FFE. Unmodified medical procedure masks with ear loops had an FFE of 38.5%±11.2%. All modifications evaluated here increased procedure mask FFE (range from 60.3%±11.1% to 80.2%±3.1%) with a nylon hosiery sleeve placed over the procedure mask producing the greatest improvement. Conclusions and Relevance: While modifications to improve medical procedure mask fit can enhance the effectiveness of procedure masks as personal protective equipment, we demonstrate the practical effectiveness of consumer-grade masks available to the public to be, in many cases, nearly equivalent to or better than their medical mask counterparts.