Ultraviolet germicidal irradiation (UVGI) is an infection control strategy that is used to reduce the spread of the airborne pathogen. It uses short-wavelength UV light to kill microorganisms and it Is a non-chemical technology with no residual byproducts. The UV light used in UVGI technology is a form of electromagnetic radiation with a wavelength from 10 nm to 400 nm, it is shorter than that of visible light but longer than x-rays and constitutes about 10% of the total electromagnetic radiation output from the sun. UV light is measured in wavelength and is generally divided into three categories based on the wavelength of the light and all of them are invisible to the human eye and are: –
- UV-A has the longest wavelength of 315 nm to 400 nm founded most abundantly in the sunlight and is responsible for skin tanning and wrinkles
- UV-B having a medium wavelength of 280 nm to 320 nm and is mostly responsible for skin reddening and skin cancer
- UV-C having a short wavelength of 200 nm to 280 nm and it is the most effective wavelength having germicidal properties.
UV-C light completely absorbed by the atmosphere and never reaches the earth’s surface therefore it is novel to coronavirus and can destroy its ability to replicate while the other two rays UV-A and UV-B have limited germicidal ability because bacteria and viruses have had millions of years to adapt to them. UV-C germicidal wavelength at 260 nm is the most effective to kill harmful microorganisms in the air, water and on surfaces. The most common wavelength for germicidal light is 254 nm that is produced by a low-pressure mercury lamp but may not be the optimal wavelength for killing all viruses. The light of 254nm wavelength is strongly absorbed by viral DNA and RNA and damage them resulting in the lack of necessary material to replicate. Shorter wavelengths range from 207nm-222nm have the Ability to destroy the proteins on the surface of the virus that is required to attach to human cells. The curve that describes the virus killing ability of UV-C light has a double-humped shape with a peak at shorter wavelengths.
According to some experts far UV-C light of 222 nm wavelength can kill coronavirus without harming humans. Far UV-C light can’t penetrate through the outer dead cell layer of human skin or tear layer in the eye so it is harmless for humans but because virus and bacteria are much smaller than human cell it can reach their DNA and can destroy them. Studies have shown that far UVC light at 222 nm wavelength can inactivate more than 95% of airborne aerosolised viruses at a low dose of 2mJ/cm2 and it is safer to use than a 254 nm germicidal wavelength. A continuous appropriate dose rate far UVC light could be integrated into overhead UVGI lamps for hospitals, schools, airports and so on can drastically reduce the spread of viruses like coronavirus and is safe for humans.
MG COOLING SOLUTIONS a leading HVAC enterprise knows that your safety is priceless in the pandemic situation and we are committed to our clients using environmentally friendly UVGI Technology to disinfect the air, water and surface in your facility.