But how well do they work? Maybe not as good as people think, says the Food and Drug Administration.
Lamps that use ultraviolet light to kill germs can inactivate coronavirus, but they are not always safe and it is not clear how well a job they do in killing the virus, the FDA says in a newly released advice.
Ultraviolet light is part of the electromagnetic spectrum emitted by the sun and can also be produced by incandescent lamps. UVC rays are absorbed by the ozone in the earth’s atmosphere ozone, but rays of UVA and UVB reach the earth’s surface and can cause sunburn and skin cancer if people get too much.
The FDA said UVC wavelengths are better than UVA and UVB light at destroying viruses, but UVC lamps have their limits.
Plus the lamps only work in limited conditions, which do not mimic many situations in real life.
“It is important to recognize that UVC generally cannot inactivate a virus or bacterium if it is not directly exposed to UVC. In other words, the virus or bacteria will not become inactive if it is covered with dust or soil, embedded in porous surface as at the bottom of a surface, “the FDA said.
There are real dangers
An explosion has been reported to fight coronavirus, including germicidal lamps. The World Health Organization warns against trying to use them to disinfect human skin, including the hands.
When a light will inactivate a virus, it takes both time and intensity to do so. A rapid flash of dim light will not damage a virus, and if it is strong enough to take a virus apart, it can damage human skin and especially tender eyes.
“Direct exposure of skin and eyes to UVC radiation from some UVC lamps can cause painful eye injury and burning skin reactions,” warns the FDA. “Never look directly at a UVC lamp source, not even briefly.”
In addition, some UVC lamps generate ozone, which can irritate the airways. “UVC can degrade certain materials, such as plastics, polymers, and dyed textiles,” the FDA added.
“Some UVC lamps contain mercury. Because mercury itself is toxic in small quantities, extreme caution is required when cleaning a broken lamp and when removing the lamp.”
Pulsed xenon lamps can be used to disinfect hospital rooms, but the bright light means they are used when people are not in the room, the FDA said.
LED lamps can produce UV radiation, but they do not cover much area, making them “less effective for germicidal applications,” the FDA said.
CNN’s Sandee LaMotte contributed to this story.
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