EPA Research Partner Support Story: Evaluating filtering and disinfection efficiency of various face coverings

Partner: University of North Carolina (UNC) Medical Center 
Challenge: Urgent shortage of respirators caused by the emerging COVID-19 pandemic
Resource: Performance evaluation of sub-optimal and alternative respirators
Project Period: 2020 – 2022

In March 2020, UNC Hospital staff faced an urgent, acute shortage of disposable N95 respirators caused by a nationwide supply shortage coupled with a sharp increase in demand, the result of the emerging COVID 19 pandemic in the U.S. A broad variety of face coverings have been adopted, ranging from improvised and homemade designs to mass-produced disposable or reusable masks. However, little guidance or information exists on the comparative effectiveness of these face coverings.

“A true silver lining of the COVID pandemic is that it has created opportunities for scientists across different disciplines and backgrounds to work together to answer meaningful and practical questions with excellent science. Aerosol scientists from the US EPA and UNC Center for Environmental Medicine, Asthma, and Lung Biology worked closely with epidemiologists from UNC Hospitals to characterize the efficacy of face masks for reducing exposure to COVID-19. The EPA scientists were able to pivot quickly to address the needs of the Hospital because of the standing infrastructure and complementary expertise supported by the EPA-UNC Cooperative Agreement.” – UNC-Chapel Hill Professor of Medicine William Bennett, PhD

In response, hospital staff approached EPA researchers for assistance evaluating the performance of respirators that had been sterilized, were past their expiration date or mis-sized, as well as respirator alternatives from around the globe. In a series of studies, EPA ORD researchers evaluated nearly 30 different types of face coverings, as well as how their effectiveness was impacted by actions such as talking and bending, double masking, and by user characteristics such as facial hair.

“These kinds of studies exemplify the importance of the working relationship between academia and applied public health. This study will shed light on what has been one of the most challenging and disheartening aspects of the COVID pandemic. Comparative effectiveness of face coverings is an essential issue for our health care professionals and for the general public. And it is important to be clear that not everyone needs the same level of protection.” – ASTHO Chief Medical Officer Marcus Plescia, MD MPH

This information can guide public health professionals in prioritizing the supply of available personal protective equipment during emergencies and will advance the understanding of factors and practices that influence the effectiveness of face coverings. 

Related Publications:

• Filtration Efficiency of Hospital Face Mask Alternatives Available for Use During the COVID-19 Pandemic
• Evaluation of Cloth Masks and Modified Procedure Masks as Personal Protective Equipment for the Public During the COVID-19 Pandemic
• A novel method for the quantitative assessment of the fitted containment efficiency of face coverings
• Can disposable masks be worn more than once?
• Improvement in Fitted Filtration Efficiency of N95 Respirators with Escalating Instruction of the Wearer
• Research Letter: Fitted Filtration Efficiency of Double Masking During the COVID-19 Pandemic
• Assessing the effect of beard hair lengths on face masks used as personal protective equipment during the COVID-19 pandemic