High‐Efficiency Particulate Air Filters in the Era of COVID‐19: Function and Efficacy

Aerosol‐generating procedures in the office represent a major concern for health care–associated infection of patients and health care providers by SARS‐CoV‐2, the causative agent for coronavirus disease 2019 (COVID‐19). Although the Centers for Disease Control and Prevention has not yet provided any recommendations for the use of portable air purifiers, air purifiers with high‐efficiency particulate air (HEPA) filters have been discussed as an adjunctive means for decontamination of SARS‐CoV‐2 aerosols in health care settings. This commentary discusses HEPA filter mechanisms of action, decontamination time based on efficiency and flow rate, theoretical application to SARS‐CoV‐2, and limitations. HEPA filter functionality and prior guidance from the Centers for Disease Control and Prevention for SARS‐CoV‐1 suggest theoretical efficacy for HEPA filters to decontaminate airborne SARS‐CoV‐2, although direct studies for SARS‐CoV‐2 have not been performed. Any portable HEPA purifier utilization for SARS‐CoV‐2 should be considered an adjunctive infection control measure and undertaken with knowledge of HEPA filter functionality and limitations in mind.