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Study: Ultraviolet LED Lights Can Kill Coronavirus

Illustration of a coronavirus particle on a UV lighted background.

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Key Takeaways

  • A new study shows LEDs that emit ultraviolet light can kill the virus that causes COVID-19.
  • The UV lights can kill coronaviruses in less than 30 seconds.
  • Researchers say that eventually the technology could be used in vacuums and air conditioners.

In a first-of-its-kind study, researchers have proven that coronaviruses can be quickly and efficiently killed using ultraviolet light-emitting diodes (UV-LEDs).

The study, which was published in the Journal of Photochemistry and Photobiology B: Biology, analyzed the disinfection efficiency of UV-LED irradiation at different wavelengths or frequencies on a virus from the family of coronaviruses.

The researchers found that the optimal wavelength for killing HCoV-OC43, a coronavirus strain used as a surrogate for SARS-CoV-2 because of their similarities, was 265 nanometers. However, a wavelength of 285 nanometers had a similar result, which matters because 285-nanometer bulbs are much less expensive than 265-nanometer bulbs.

The wavelengths took less than 30 seconds to destroy more than 99.9% of the coronaviruses.

“UV disinfection has been around for a while, but UV-LEDs are still very new, and so is their use,” lead study author Yoram Gerchman, PhD, a biochemist and professor at the University of Haifa and Oranim College in Isreal, tells Verywell. “Part of the problem is, the lower the wavelength, the more expensive and less efficient is the UV-LED, so there is much interest in the higher wavelength.”

Gerchman says that his paper is an “important step” in using UV-LED devices for disinfecting purposes.

What Is UV Light?

Ultraviolet light is a type of electromagnetic radiation. It’s mostly invisible to the human eye and travels in a wavelength pattern at the speed of light.

The numbers that are used to measure UV light describe the activity level, or how energetic the photons in the light are, as well as the size of the wavelength.

The most common form of UV radiation is sunlight, which produces UVA, UVB, and UVC rays. UVA rays have the longest wavelengths, followed by UVB, and finally UVC rays.

UVA and UVB rays are transmitted through the atmosphere. All UVC rays are absorbed by the Earth’s ozone layer, but the UVC rays are often used in commercial light disinfecting devices. UV-LEDs are a form of UVC lights.

Lewis Nelson, MD, chair of the Department of Emergency Medicine at Rutgers New Jersey Medical School, tells Verywell that the findings are “not at all” surprising. Nelson did not work on the study. Other forms of UV light have already been used for disinfecting purposes, and there's no reason to think that UV-LED light would be any different.

How UV-LED Light Can Be Used

While UVC lights are used commercially in products like phone disinfecting devices, UVC light can cause severe burns of the skin and eye injuries. “They need to be properly positioned to avoid causing eye or skin damage, which is essentially sunburn,” Nelson says.

Many UVC disinfecting products work inside a case or box to prevent people from being harmed by the rays. However, that arrangement makes it tricky to use UVC on a larger scale for disinfecting homes.

Yoram Gerchman, PhD

UV in general and UV-LEDs are effective in combatting pathogens, [but] UV should be used carefully.

— Yoram Gerchman, PhD

Gerchman proposes using UV-LED lights in air conditioning systems to help filter air that might contain SARS-CoV-2, which "could help in reducing exposure."

The study's co-authors also proposed using the technology in vacuum and water systems to quickly and efficiently disinfect large surfaces and spaces. Gerchman says that “UV in general and UV-LEDs are effective in combatting pathogens,” but adds that “UV should be used carefully.”

“I believe we are nearing the end of the COVID-19 [pandemic] with the vaccination approval, but airborne and waterborne pathogens—especially antibiotic resistance pathogens—will be with us for many years to follow,” Gerchman says. “UV is and will take part in battling such.”

What This Means For You

One day, UV-LED light could be another tool to help prevent the spread of SARS-CoV-2 and other coronaviruses. However, as of right now, it is not recommended for commercial use.

The information in this article is current as of the date listed, which means newer information may be available when you read this. For the most recent updates on COVID-19, visit our coronavirus news page.

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2 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Gerchman Y, Mamane H, Friedman N, Mandelboim M. UV-LED disinfection of Coronavirus: Wavelength effectJ Photochem Photobiol B. 2020;212:112044. doi:10.1016/j.jphotobiol.2020.112044

  2. U.S. Food and Drug Administration (FDA). Ultraviolet (UV) Radiation. Updated August 19, 2020.