CDC Fact Sheet Discusses Upper-Room Ultraviolet Germicidal Irradiation

A new webpage published by CDC focuses on upper-room ultraviolet germicidal irradiation (UVGI), which the agency says can be effective at reducing exposures to SARS-CoV-2 in some group settings. UVGI is the use of ultraviolet energy to kill viral, bacterial, and fungal organisms, and upper-room UVGI describes a disinfection zone of UV energy located above people in occupied rooms. According to CDC, UVGI kills airborne pathogens in the room where they are released, and fixtures are installed to prevent direct UV exposures to people in the room. The agency recommends UVGI for indoor spaces with insufficient or no mechanical HVAC systems or spaces where adequate natural ventilation cannot be maintained year-round. UVGI can be used in high-risk indoor settings such as hospital waiting rooms and other areas where sick people are likely to be; crowded spaces like lobbies; restaurants, break rooms, cafeterias, and other places where people remove masks to eat or drink; and areas where it is difficult to maintain six feet of distance from others.

CDC notes that UVGI does not replace the need for cleaning or disinfecting surfaces where infectious SARS-CoV-2 droplets may be present. The agency adds that upper-room UVGI “would not add as much benefit” in a space where the HVAC system allows for efficient filtration or provides outdoor airflow above minimum code requirements.

The new page also discusses considerations for installation, maintenance, implementation, and selection of upper-room UVGI systems.