EPA, along with their co-authors at UNC, recently published an article titled “Fitted Filtration Efficiency of Double Masking During the COVID-19 Pandemic” in JAMA Internal Medicine. With global vaccination efforts against SARS-CoV-2 rapidly increasing, public health officials have continued to encourage the use of face masks to mitigate virus transmission. The article addresses the limitations of a previous study done by US Centers for Disease Control and Prevention (CDC), which reported that wearing two masks increased the effectiveness of preventing spread of COVID-19. This study considers the limitations of the CDC’s research on type and combinations of different masks as well as the CDC’s use of head forms rather than humans. This study compared the fitted filtration efficiency (FFE) of the most widely available masks worn singly, doubled, or in combinations.
Results demonstrated that the most significant improvement to FFE occurred from the combination of a medical procedure mask worn underneath a cloth mask, out of all combinations considered.