Ultraviolet (UV) light is a useful tool for thorough disinfection and sanitation, according to Larson Electronics. Specifically, the UV-C range (wavelengths ranging between 200 nm and 280 nm) is capable of eliminating viruses, bacteria, mold and spores – including the COVID-19 corona virus, severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS), e. coli, yeast and more. This solution is being used in large-scale wastewater treatment, medical facilities, laboratories, manufacturing, food processing and hospitals.
How Does it Work?
During the disinfection process, UV-C light targets the DNA of the microbe. Exposure to the light causes thymine dimers to form in the DNA. As more thymine dimers are formed, damage starts to accumulate inside the DNA. Bumps also appear in the DNA as a result of the dimers. These cellular mutations negatively affect growth and the risk of non-repair increases. Eventually, the damage becomes too extensive and the cell dies. DNA replication is stopped, which reduces infection or spread rate of the virus.
UV-C Light and Viruses
UV light has been tested as an effective solution against a myriad of viruses. According to an article published in Journal of Virological Methods, SARS caused by the corona virus (SARS-CoV) is eliminated through exposure to UV light in the 254 nm range. UV treatment has also been found to kill MERS or MERS-CoV, a type of corona virus that emerged in 2012. In a study published in the US National Institutes of Health's National Library of Medicine (NIH/NLM), UV-C light deactivated MERS-CoV within 5-10 minutes of exposure.
When it comes to the latest outbreak of COVID-19, UV light has been confirmed to be effective in eliminating the virus by Juan Leon, an environmental health scientist at Emory University, and Dr. Lena Ciric, an associate professor at University College London. UV-C treatment is already proven to work on previous strains of the corona virus, i.e. SARS-CoV and MERS-CoV, as mentioned above. Therefore, it makes sense for the light to be used against COVID-19.
Unlike liquid cleaning agents, no contact with the surface or device is required when sanitizing with UV-C light. It does not leave a residue or cause discoloration after the process. There is no downtime after sterilization – the area or equipment can be used immediately after disinfection. It is important to consider that the longer the surface, area or device is treated by the UV light, the higher the disinfection rate. This is because more thymine dimers are generated in the DNA of the virus. Furthermore, the UV light should be intense to ensure thorough sanitation. The effectiveness of the light decreases as the distance from the light increases.