How Does UV-C Light Kill viruses?
Ultraviolet germicidal irradiation (UVGI) is a disinfection method that uses short- wavelength ultraviolet (ultraviolet C or UV-C) light to kill or inactivate microorganisms by destroying nucleic acids and disrupting their DNA, leaving them unable to perform vital cellular functions.
On the electromagnetic spectrum, not all kinds of UV are effective in terms of germicidal irradiation. UV is divided into three types with reducing wavelengths and increasing energy. They are UVA, UVB and UVC.
UVC radiation, in the range of 250 nm – 280 nm, renders harmful micro-organisms such as bacteria and viruses ineffective, by destroying the genetic information in the DNA. The micro-organisms lose their reproductive capability and are destroyed. The germicidal nature of UV is well suited to treat parasites which are extremely resistant to chemical disinfectants.
For UV disinfection, only UVC (200-280nm) has high enough energy to effectively kill microorganisms.
The entire UV spectrum can kill or inactivate many microorganism species, preventing them from replicating. UVC energy at 253.7 nanometers provides the most germicidal effect. The application of UVC energy to inactivate microorganisms is also known as Germicidal Irradiation or UVGI.