As part of President Biden's National COVID-19 Preparedness Plan, the U.S. Environmental Protection Agency is releasing the "Clean Air in Buildings Challenge," a call to action and a concise set of guiding principles and actions to assist building owners and operators with reducing risks from airborne viruses and other contaminants indoors. The Clean Air in Buildings Challenge highlights a range of recommendations and resources available to assist with improving ventilation and indoor air quality, which can help to better protect the health of building occupants and reduce the risk of COVID-19 spread.