The UVC germicidal lamp is a germicidal disinfection device equipped with a UVC germicidal lamp light source, widely used for sterilization of indoor surfaces and air, using UVC quartz lamps emitting wavelengths of 185nm and (or) 254nm to kill harmful microorganisms by direct irradiation. Some products also produce a certain concentration of ozone to kill microorganisms.
During the new coronary pneumonia epidemic, news that the coronary virus was sensitive to UV light and heat made UVC germicidal lamps hot in the market, and at one point there was a shortage of supply on the market.
In fact, UV germicidal lamps emit ultraviolet light will also produce irradiation damage to the human body, and UV light for invisible light, if the structure is not designed, is easy to misuse and lead to human skin, and eye injury.
Can UV LEDs kill new coronaviruses?
In a recent study, researchers found that ultraviolet light-emitting diodes (LEDs) can quickly and effectively kill the human coronavirus HCoV-OC43. This is the first study to address the disinfection efficiency of viruses in the coronavirus family in response to UV-LED radiation at different wavelengths or frequencies. Completed by a team led by Professor Hadas Mamane from Tel Aviv University, the article was published in the November 2020 issue of the Journal of Photochemistry and Photobiology.
Using human coronavirus OC43 (HCoV-OC43) as an alternative to SARS-CoV-2, the team tested different UV LED bulbs (emitting different wavelengths – in nm) to see which wavelength effectively inactivated the HCoV-OC43 virus.
After exposing a suspension of the virus placed in a dark tube to UV LED light, the team found that the 285nm wavelength was very effective in inactivating the virus, almost as effective as the 265nm wavelength, inactivating 99.9% of coronaviruses within 30 seconds.
In addition, other viruses show similar sensitivity to these wavelengths, suggesting that this technique could be used against many types of human coronaviruses, including SARS-CoV-2.
The researchers say the findings are significant because the 285nm UV LED light not only disinfects coronaviruses but is also cheaper and more readily available than the 265nm variety.
Deep UV effectively inactivates SARS-CoV-2
Unlike traditional chemical sterilization methods, deep UV light sources can directly dissociate the genetic carriers inside bacteria and viruses, which has the advantage of high sterilization efficiency and no continuous damage.
A joint research team from the Graduate School of Medical Dentistry Research Department (BMS) at Tokushima University and the University’s Post-LED Photonics Institute (pLED) has successfully inactivated the new coronavirus (SARS-CoV-2) using deep ultraviolet light (over 99.9% inactivation rate), quantified the amount of light required, and obtained basic inactivation data that can be applied to any environment, including liquids and air. This will provide a basis for performance evaluation when producing new coronavirus inactivation devices.
Results of experiments using deep UV LEDs to inactivate the New Coronavirus. It is possible to see how much virus can be inactivated by irradiating for how long with how many wavelengths and how much power.
UV LED lights kill coronavirus – rumor or science?
Now looking at the issue again, it is not a rumor that UVC germicidal lamps that meet international standards are indeed effective in inactivating coronaviruses.
The UVC band refers to ultraviolet light with a wavelength of 200-280nm, also known as the deep ultraviolet band, which is capable of damaging the DNA and RNA chains of bacteria or viruses, rendering them incapable of replicating or reproducing, thus achieving truly effective germicidal inactivation.
The correct use of UV light can destroy the new coronavirus, but the claim that the infectious pathogenicity of the new coronavirus can be reduced in 0.3 seconds is not rigorous. The ability to destroy the virus faster and better depends primarily on the dose of UV light. The dose of UV is influenced by the optical power of the UV, i.e. the amount of light energy per unit area.
The higher the light power, the higher the dose of UV at the same wavelength, and naturally the shorter the sterilization time. Therefore, only with a sufficiently high light power is it possible to achieve 0.3 seconds for the elimination of the new coronavirus.