Filtration Efficiencies of Face Mask Alternatives During the COVID-19 Pandemic

Procuring sufficient personal protective equipment (PPE) has been challenging during the COVID-19 pandemic. As a result, healthcare organizations have considered nonstandard practices, including using expired masks and reusing masks after sterilization. In this study, researchers tested the fitted filtration efficiencies (FFEs) for 29 different face mask alternatives.

For each mask alternative, FFEs were determined by sampling aerosol inside the face mask for one man and one woman. Nearly all new National Institute for Occupational Safety and Health (NIOSH)-approved N95 respirators had FFEs >95%. NIOSH-approved respirators with intact elastic straps that were expired (as long as 11 years) or reused after sterilization (e.g., with ethylene ox…