UV-A, UV-B, and UV-C all are forms of ultraviolet light rays that are classified according to their wavelengths. These are naturally occurring phenomena with sun being the most significant source of ultraviolet rays. Studies prove that UV light is primarily a product of nuclear reaction at the sun’s core that reaches the earth via the sun’s rays.
Moreover, it can also be emitted by man-made products like UV luminaires, lasers, welding torches, and tanning beds. In fact, UV light is capable of damaging the RNA and DNA of microbes and pathogens. Thus, it can be used to disinfect a space and prevent the spread of bacteria and viruses, especially during this critical pandemic time. However, it is extremely important to gain an understanding of UV lights before using them as they can be harmful if not managed properly.
UV-A light has the longest wavelength and lowest energy levels of all the three types. Its wavelength can vary from 315nm to 400nm. It is more penetrating than UV-B rays and can cause indirect damage to the microbe’s DNA. Moreover, it produces intra cellular reactive oxygen species that can kill viruses and bacteria. However, UV-A light is a part of the visible light spectrum and is majorly safe for human beings.
UV-B light has the second longest wavelength (280nm -213nm) following the UV-A light. However, it tends to have higher energy levels than the latter. It is capable of directly damaging the DNA of microbes and overexposure may lead to delayed sunburns. Interestingly, a major amount of the naturally occurring UV-B light is absorbed by the ozone layer and only a small amount reaches the earth. However, it is associated with high risk of skin cancer, hence considered unsafe for humans.
UV-C light has the shortest wavelength (200nm – 280nm) and highest energy levels of all the three types. However, due to its short wavelength, most of the naturally occurring UV-C rays are completely absorbed by the ozone layer. Moreover, UV-C light is the most germicidal in nature. It is capable of breaking down the chemical bonds found in microorganisms and pathogens and destroying them. Thus, it serves as a great way to decontaminate surfaces. For instance, it is used in portable disinfectants such as ULTRARAY™ CUBIX by Wipro Lighting.
UV-C being the most effective germicidal is used in a variety of application areas like water purification, air purification, and hospital sanitization. We at Wipro Lighting have also harnessed the power of UV-C rays in our commercial lighting solution ULTRARAY™ for making workplaces safer for the people.