Harvard Health Portable Air Cleaners Study

This document is intended to provide an overview of the principles and application of portable air cleaners to reduce the risk of transmission of COVID-19. Before continuing with this document, we present this reminder that this strategy should be considered within the larger context of holistic risk reduction strategies. We advocate a layered defense approach based on the ‘hierarchy of controls’, of which engineering controls and Healthy Buildings strategies are one critical component. We also caution that this document on portable air cleaners addresses one mode of COVID-19 transmission – airborne – but does not address transmission through close contact (large droplets and aerosols) or contaminated surfaces.

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