The U.S. Food and Drug Administration (FDA) recently released a statement regarding the use of ultraviolet light for disinfecting amidst the COVID-19 pandemic.
Ultraviolet-C (UVC) lamps, also known as “germicidal” lamps, emit radiation that can disinfect volumes of air, water, as well as nonporous surfaces like concrete. It has been used effectively to help limit bacterial spread.
While FDA has stated that UVC has the ability to deactivate viral cells, there are some limitations in that the light can only eliminate viral particles if the surface is directly exposed to light.
FDA explained in the report that “UVC radiation can only inactivate a virus if the virus is directly exposed to the radiation. Therefore, the inactivation of viruses on surfaces may not be effective due to blocking of the UV radiation by soil, such as dust, or other contaminants such as bodily fluids.”
The FDA also indicated that even though UVC radiation has worked in the past on other viruses such as tuberculosis, and may possibly be an effective way to disable the current SARS-CoV-2 virus, there is still a limited amount of data regarding the “wavelength, dose, and duration of UVC radiation” that is necessary to effectively and safely neutralize the virus.
In addition, the FDA stated that “UVC radiation has been shown to destroy the outer protein of the SARS-Coronavirus, which is a different virus from the current SARS-CoV-2 virus,” which ultimately inactivates the virus. The agency says UVC “may” have a similar effect on SARS-CoV-2 virus.
Amidst the pandemic, people who wish to purchase UVC lamps to use for disinfection at home might not realize that these home-use UVC lamps may be emitting far less radiation than necessary to inactivate these viral particles, meaning that individuals will need to use these lamps for longer in order to effectively disable viral particles.
Extended exposure to UVC radiation may end up being harmful as well, and not all UVC lamps are the same.
“UVC lamps used for disinfection purposes may pose potential health and safety risks depending on the UVC wavelength, dosage, and duration of radiation exposure,” the FDA said. It went on to say that potential health risks could possibly increase if UVC lamps aren’t installed properly or used by untrained individuals.
The health risks include eye injuries to varying degrees as well as skin injuries similar to that of a burn. Certain UVC lights contain mercury, which is an element that is toxic even in the smallest amounts. If not being careful, cleaning a lamp could be dangerous.
In addition, certain UVC lamps generate ozone that can be harmful during prolonged use, and generate problems such as irritation to the nose, throat, and lungs, as well as respiratory disease, if severe enough.
UVC rays are one of the three ultraviolet rays emitted by the sun, next to UVA and UVB. While UVA and UVB are able to penetrate the earth’s ozone, UVC can only be found in artificial sources like UVC lamps.
It’s commonly used inside air ducts to disinfect the air.
