1. Enforcement policy for face masks, barrier face coverings, face shields, surgical masks, and respirators during the coronavirus disease (COVID-19) public health emergency (revised): guidance for industry and Food and Drug Administration staff Publication: [Silver Spring, MD] : Center for Devices and Radiological Health, September 2021 Subject(s): COVID-19MasksN95 RespiratorsPersonal Protective EquipmentRespiratory Protective DevicesUnited StatesUnited States. Department of Health and Human ServicesUnited States. Food and Drug Administration
