UVC light is used to disinfect objects and surfaces.
Ultraviolet (UV) light is produced by the sun and by special lamps. There are three types of UV light—UVA, UVB, and UVC. UVC light has the most energy of the three types. This energy destroys the genetic material inside viruses and other microbes. Therefore, UVC light is used for disinfection. UVC lamps and robots are commonly used to sanitize water, objects such as laboratory equipment, and spaces such as buses and airplanes.
UVC light probably destroys the novel coronavirus, but we need to learn more.
UVC light has been found to destroy viruses and other microbes on surfaces in hospitals. But it is not widely used in hospitals or other health care settings. The U.S. government and the UV technology industry are working to define standards for UV disinfection technologies in healthcare settings.
Most UV sanitizers have not been tested against the novel coronavirus, SARS-CoV-2. But UVC light been shown to destroy related coronaviruses, including the one that causes the disease MERS.
It is not safe to use UV sanitizers on your body.
Exposure to UVC light is dangerous for people.
- UVC sanitizers can damage your eyes and skin.
- UV light can cause cancer.
- Scientists are exploring ways to use a specific type of UVC light for devices that could be safe for humans. However, existing products are not safe to use on your body.
UVC wands, pouches, and lamps are also sold for home use—for example, disinfecting your cell phone. However, the safety and effectiveness of these products is not known. Beware of false claims that say these products are effective or are for use on humans.
Sunlight does not destroy the coronavirus quickly.
UVC light from the sun is blocked by Earth’s atmosphere. When you go outside on a sunny day, the UV light that reaches you is UVA and some UVB. These types of UV light do not destroy viruses quickly.
- Going outside on a sunny day will not quickly break down coronaviruses on skin. But it can give you a sunburn if you are not wearing sunscreen!
- Some viruses are seasonal and spread more slowly in the summer. This is probably due to warmer temperatures, higher humidity, and changes in human behaviors—not because it is sunnier in the summer.
- The best ways to protect yourself from COVID-19 are to wash your hands, keep your distance from other people, and clean and disinfect frequently touched surfaces.