CONSUMER REPORTS — Hospitals have been using ultraviolet lights for years to kill bacteria and viruses and to disinfect surgical areas. That same technology is also sold as wands and other UV products you can use at home. Consumer Reports looks into the science behind UV sanitizing lights.
Ultraviolet technology isn’t new. It’s been used in hospitals, research labs, and other areas that need to be germ-free. But now you may be noticing that same technology for sale everywhere from Costco to drug stores. That’s because UV light kills up to 99.9% of germs, bacteria, and viruses, and that may include the coronavirus.
“The thing about ultraviolet is it is of sufficient energy to cause damage to cells, DNA, and other biological material, which can make it a powerful disinfectant against viruses and bacteria,” said James Dickerson, Consumer Reports Chief Scientist.
Most of the lights you’ll see for sale are UVC. But before you stock up, there are some things you should know. The light needs direct exposure to the intended surface to kill the coronavirus. That means if the beam of light can be blocked by dust, or dirt, or even small crevices, any impediment, the UV light may not be fully effective. Also, many of the UV lamps sold for home-use are low dose, so it may take a longer exposure to a given surface area to potentially provide effective inactivation of a bacteria or virus. Waving the light quickly over your countertops likely will not be enough. And because UV can burn eyes and skin, never ever look directly at it.
“Some devices turn off when opened, but if you own a product with an exposed UV lamp, never look directly at the light,” Dickerson said.
If you’ll be purchasing one of the UV sanitizing lights, be wary that UVC light can degrade certain materials, like plastic, polymers, and dyed textiles.