UV light could be used as a disinfectant against COVID-19 but only in specific contexts and not on human skin
Ultraviolet light could kill the coronavirus (SARS-CoV2)
Accurate as a whole (with reservations)
Health Europa published an article on 2 June 2020 suggesting that Ultraviolet light (UV light) could kill the coronavirus that causes COVID-19. Our verdict is that this is accurate, with reservations.
The authors explain that although it would take very high levels, UV light has potential uses for decontamination of public spaces and surfaces. Researchers from Penn State and the University of Minnesota are investigating UV radiation and the possibility of creating devices that emit a specific kind of UV light to kill virus particles. While this is accurate as a whole, there are other important factors to keep in mind: 1- there are different kinds of UV light and they do not all disinfect at the same rate; and 2 - while some UV light can disinfect surfaces, they should never be used to disinfect our skin.
Different kinds of UV Light
The World Health Organization (WHO) explains there are three different kinds of Ultraviolet (UV) radiation, categorized according to their wavelength: UVA, UVB, and UVC. UVA can penetrate deep into the skin, causes tanning, ageing and wrinkling and contributes to the development of skin cancer. UVB can only penetrate the superficial layers of skin, causes sun burns and significantly contributes to the development of skin cancer. UVC can cause the most damage but is filtered out by the earth’s atmosphere. UV radiation is emitted by the sun naturally and by artificial sources, like tanning beds or mercury vapor lighting.
Not all UV light has the same disinfectant abilities on surfaces and products
UV radiation is used to disinfect water, as it inactivates pathogens like viruses and bacteria. There are studies, such as in Applied and Environmental Microbiology and Journal of Occupational and Environmental Hygiene, where UV radiation is shown to successfully disinfect surfaces. Ultraviolet germicidal irradiation is a disinfection method that uses UVC to kill or inactivate microbes and viruses. While it can be used to disinfect respirators for hospitals, the US Centers for Disease Control and Prevention warned that the effectiveness of UV radiation as a surface disinfectant is not yet known.
The National Academies of Sciences, Engineering and Medicine reported (US) that UVC light can “probably” destroy the virus that causes COVID-19 on surfaces, while including several specific stipulations. UVC light can destroy other viruses and microbes, including other coronaviruses and the one that causes Middle East Respiratory Syndrome. However, it is still not officially proven and there is still a lot of research and studies that need to be completed to officially confirm or deny it. Furthermore, UV light should not be used to disinfect skin.
UV light can work on inanimate surfaces, but should not be used on the skin
There is a difference between skin and surfaces of inanimate objects. The WHO warned not to use UV lights to disinfect the hands or skin, as the UV radiation can damage your eyes and cause skin irritation. The WHO explained that UV light can damage eyes, sometimes causing eye cancer or leading to cataracts. As the US CDC explained overexposure to UV radiation can cause skin damage and serious health issues, including skin cancer. Instead, you should use an alcohol-based hand rub or wash your hands with soap and water for twenty seconds. To wash your body, use soap and water.
While hospitals and businesses use UV radiation as a disinfectant, these devices are different from those sold to consumers. According to the International Ultraviolet Association (IUVA), there is no standardization in the construction of UV devices, so they have a wide range of performance abilities that may or may not effectively and efficiently disinfect. The IUVA also warned against consumer devices sold on platforms like Amazon, as they are unregulated and are not guaranteed to perform effectively. The IUVA advised to look for certification by NSF, UL, CSA. Devices like tanning beds emit UVA and UVB, which cannot be used to disinfect surfaces. They do not emit UVC, which can cause extreme damage to the skin.
The US Food and Drug Administration warned that while UV light products can be used to disinfect surfaces, to be used safely, they should shield the user from exposure to the light, otherwise it risks doing more harm than good.
While UV radiation can be used as a disinfectant, not all types of UV light are effective. They should not be exclusively relied on and should never be used on the skin. Physical distancing, wearing a mask when that’s not possible, frequent handwashing and routinely cleaning frequently touched surfaces in the home remain the best defence against COVID-19.
Before taking action, research your subject
In uncertain times, we all want to find answers and ways to protect ourselves and our loved ones. When we read about potential defences against COVID-19, it’s easy to get caught up in the “what if” and the seemingly logical reasonings that are put forth by well-meaning people, journalists who may not have a health background or have had their scientific claims checked by a scientist or health professional, or by studies which have not been peer-reviewed. Before venturing into the unknown even more by trying prevention methods that have not been recommended through scientific consensus or trusted health authorities, it is important to research or fact-check claims.
From the perspective of communicating science, there is an immense amount of research being conducted in a short period of time with the emergence of the novel coronavirus. The United Nations Educational, Scientific and Cultural Organization (UNESCO) promotes an open science model because it stimulates collaboration and dialogue between scientists and allows the public to be aware of the evolving situation. WHO is using the term “infodemic, coined by Canadian researcher Gunther Eysenbach in 2002, to describe the overabundance of information — some of which is true and some of which is false. A lot of this information and data is being released as “pre-prints”, which are scientific journal articles that have not been reviewed by peers yet, or disseminated by pharmaceutical companies or other organisations. The rigor of the science they are describing is sometimes questionable, the limitations are not clearly spelled out, and the results may just be preliminary. The implications of the studies are prone to misinterpretation and misunderstandings because the public and news media are ill equipped to filter, assess, or contextualize scientific information.
Click here to learn more on the effectiveness of UV rays against COVID-19.
Applied Environmental Microbiology https://aem.asm.org/content/82/5/1468
Journal of Occupational and Environmental Hygiene https://www.tandfonline.com/doi/abs/10.1080/15459624.2016.1166369?journalCode=uoeh20
National Academies of Sciences, Engineering and Medicine https://sites.nationalacademies.org/BasedOnScience/covid-19-does-ultraviolet-light-kill-the-coronavirus/index.htm
The US Centers for Disease Control and Prevention https://www.cdc.gov/coronavirus/2019-ncov/community/disinfecting-building-facility.html
The International Ultraviolet Association https://iuva.org/IUVA-Fact-Sheet-on-UV-Disinfection-for-COVID-19 https://iuva.org/iuva-covid-19-faq
Ultraviolet light could kill the coronavirus (SARS-CoV2)
July 10, 2020
Learn more about our fact-checking methodology HERE.