Can UV Lights Kill Coronavirus?

With the COVID19 pandemic rapidly spreading throughout the world, we all want to do everything we can to keep ourselves and our families safe. Because they are invisible to the naked eye, however, we can never be certain if we have been able to properly disinfect ourselves and our belongings. In addition to good hygiene practices, you may also be wondering what tools and technologies can be used to sterilize and eliminate coronavirus particles in our homes.

You may have come across UV lights that are marketed specifically for sterilization and disinfection, and be wondering if they actually work? And will they effectively kill the SARS-CoV-2 coronavirus? We've put together some information below that might help answer these questions.

Disclaimer: The information below is provided by Waveform Lighting for educational purposes only. None of the content provided on this website is medical advice, and we do not take any responsibility for physical or financial harm and/or illness caused by your use of the information below.

How Does UV Light Disinfection Work?

In very general terms, UV lights are similar in concept to regular white light sources such as fluorescent lamps and LEDs. Both take electrical energy, and convert that energy into photons, or light waves / particles.

Regular light bulbs will emit energy with wavelengths in the visible spectrum, and this of course is great, because we want this to be able to see. UV lights, on the other hand, will emit energy with wavelengths that are in the ultraviolet spectrum, which is not visible to humans. A small part of the ultraviolet spectrum, called UV-C, has been shown to be very effective for killing viruses, including the common cold coronavirus as well as the SARS coronavirus.

UV-C refers to a specific range of ultraviolet light that is between 100 and 280 nanometers (nm). Wavelengths in this range have been shown to directly destroy the DNA and RNA of pathogens including viruses, bacteria and molds, preventing them from reproducing.

Does UV-C Kill the COVID-19 coronavirus?

Because the novel coronavirus (SARS-CoV-2) responsible for the current pandemic has only recently been discovered, no laboratory tests have yet been performed to confirm if ultraviolet radiation can effectively kill this particular virus.

A significant amount of prior research, however, suggests that UV-C is likely to be capable of killing the SARS-CoV-2 coronavirus responsible for the COVID-19 pandemic. Below are three reasons UV-C will likely be effective against the COVID-19 coronavirus.

1) The mechanism behind UV-C disinfection is virtually general and robust

Disinfection of single-strand RNA viruses (such as coronaviruses) is achieved by targeting the nucleic acid called uracil, which is a vital component in the viral genome. When uracil is exposed UV-C radiation, the chemical bonds are altered, which results in a corrupted genetic code, disabling the virus' ability to reproduce.

DNA and RNA are the fundamental building blocks of viruses and all living organisms, and because the UV-C interaction occurs at such a fundamental genetic level, UV-C disinfection has been shown to be effective across virtually all types pathogens. At this point, there is no evidence that would suggest the specific viral makeup of the SARS-CoV-2 coronavirus would make it immune to the same disinfection mechanism.

2) More than 250 studies have confirmed that UV-C disinfection is effective against a wide range of viruses and strains

Due to the way in which UV-C wavelengths attack the DNA and RNA of pathogens, UV-C is a robust and reliable way to inactivate a wide range of viruses, bacteria, molds and fungi. More than 250 studies have been performed using UV-C disinfection with results showing effective inactivation of a wide range of viruses such as avian flu, hepatitis A, herpes, influenza A, and polio, as well as coronaviruses.

Despite these viruses having a wide range of differing structures and sizes ranging from double-strand DNA viruses to single-strand RNA viruses, the efficacy of the UV-C disinfection across all of these viruses suggests that the likelihood of it also being effective against the COVID-19 coronavirus is quite high.

3) UV-C tests in the past have shown successful disinfection of the common cold coronavirus as well as the SARS coronavirus

A study in a Japanese laboratory on the SARS virus showed that exposing the virus to an UV irradiance of 1.34 W/m² for 15 minutes significantly reduced the infectivity of the sample. A separate study on the same virus showed that UV-C irradiance of 40.16 W/m² resulted in a "400-fold decrease in infectious virus" after 6 minutes of exposure, with complete inactivation achieved after 15 minutes of exposure. A later 2007 study on the murine coronavirus showed that UV-C radiation resulted in successful air disinfection using a dose of 3 J/m².

Due to the structure and genetic code similarities of the SARS-CoV-2 coronavirus, it would be reasonable to consider a similar level or mechanism of susceptibility to UV-C sterilization.

Beware of Dubious Marketing and Unverified Claims!

As we have seen, previous research and our understanding of the theory behind UV-C sterilization gives us strong confidence that the SARS-CoV-2 coronavirus is susceptible to inactivation via UV-C irradiance. Even if future research verifies the ability of UV-C to kill the SARS-CoV-2 coronavirus, keep in mind that a wide variety of factors will affect the efficacy of your particular UV-C light source. For example, achieving the correct dosage of UV irradiance depends on the power of the UV device, the angle at which it is used, the distance away from the UV source as well as the irradiance time. If you are unable to achieve a sufficient dosage, your sterilization efforts may be going to waste.

Most importantly, you will want to be very certain of the accuracy and veracity of the technical specifications of the UV-C products you purchase, as unscrupulous manufacturers and sellers may choose to take advantage of the fact that both UV-C radiation and germs are invisible to the naked eye. Confirming that a UV source is truly emitting in the UV-C wavelength range is an expensive undertaking for the end consumer, as neither the product nor the result can be readily validated.

Looking to Purchase a UV-C LED Source?

Waveform Lighting has launched a line of UV-C products called cleanUV™. Click here to learn more.