Disinfecting with ultraviolet (UV) light is technology that is more than 100 years old, but it’s now having a resurgence to combat the new coronavirus. Currently approved for tuberculosis control by the Centers for Disease Control and Prevention, these commercial systems use UV-C light (also called germicidal UV) typically with a wavelength of 254 nanometers (nm). Such “upper room” UV systems utilize fixtures that create a disinfection zone that is above the occupied zone in a space, such as in factories.
However, depending on the intensity, this type of light can cause serious damage to skin and eyes in a matter of seconds.
Recent studies have found that far-UVC, with a wavelength of 222 nm, is a people-safe alternative that still has the potential to kill SARS-CoV-2, the virus that causes COVID-19, as well as flu viruses and tuberculosis. New studies are underway to confirm this.
UV-C at home: A safe way to access UV-C technology at home is to add a UV-C light to your HVAC’s filtering system. This won’t kill germs on surfaces—you should still disinfect high-touch surfaces—but it will help remove them from the circulating air. Fresh-Aire UV is one company that sells these products, though it must be professionally installed. A base system with a germicidal lamp is about $500 installed. A higher-end system that has more features to remove other contaminants, such as chemical vapors, dust and mold, would be about $900 to $1,800.
Another option is to purchase portable individual room air purifiers with built-in and fully covered sources of UV-C light. Prices range from less than $100 to several hundred dollars.
Placing one of these in the room of someone who is sick and isolating would help reduce exposure to airborne germs for those attending to him/her. In addition, if your home has a central air system and return air from the sick person’s room is not blocked, adding air cleaners in other areas also would help protect those who are not infected.
Stay away from traditional UV-C products for home use, from handheld wands to whole-room towers, that have an “open” (uncovered) UV-C light. Even if the unit has a timer, the light can harm skin and eyes if it accidentally turns on before you leave the room.