Abstract View
Effect of Valved and Unvalved N95 Respirators and Face Coverings on Exhaled Particles
ANDREW VINER, Christine McCool, David Buckley, Nicole McCullough, 3M
Abstract Number: 602
Working Group: Infectious Aerosols in the Age of COVID-19
Abstract
Face coverings have been recommended by the U.S. Centers for Disease Control and Prevention for source control to help reduce the spread of COVID-19, the disease caused by the SARS-CoV-2 virus. NIOSH-approved respirators, which decrease wearers’ exposure to potentially infectious aerosols and droplets when properly selected and worn, also provide source control; however, some respirators include exhalation valves to help exhaust exhaled air from inside the respirator and increase user comfort. The fraction of exhaled particles that penetrate through filter media, exhalation valves, and escape around the perimeter of a respirator or face covering can be defined as total outward leakage. Here we present total outward leakage measurements from valved N95 respirators, unvalved N95 respirators, and face coverings worn by human test subjects over a particle size range of 0.3-20 µm. Additionally, we present outbound particle penetration data through respirator exhalation valves for particles larger than 0.3 µm. These data provide insight into the effectiveness of face coverings and respirators as a source control for exhaled particles.