Ultraviolet light in the C-band (UV-C) is known as Ultraviolet Germicidal Irradiation (UVGI), due to its lethal effect against micro-organisms such as viruses, bacteria and other harmful microbes that pose a threat to human health.
A scientific review on a wide range of coronaviruses which includes the SARS coronavirus have concluded that SARS-CoV-2, the virus responsible for Covid-19, is highly susceptible to ultraviolet inactivation. This conclusion is based on a wide-ranging study on the effect of UVGI on coronaviruses.
The table below shows the UV-C dosage required to treat a wide range of coronaviruses and demonstrates that UVGI is effective for surface and air treatment to prevent and control the spread of this highly infectious disease.
UVGI kills or inactivates microorganisms by attacking their nucleic acids – this is the genetic material also known as DNA or RNA. UVGI causes the nucleic acids to cross-link so that it is unable to replicate and so rendering the microbe unable to grow, divide and proliferate.
UV-C is commonly used for water treatment and is becoming widespread for surface and air treatment in healthcare, commercial and residential buildings. In light of the Coronavirus pandemic, UVGI has a major part to play as an infection control solution which can be used to stop the spread of the disease.
When designing an effective UVGI system, it is important to ensure that the correct UV-C dosage is employed. This is the UV-C light energy which is used to attack the micro-organism. Too little dosage and there is no effect. Too much simply wastes power. When treating surfaces, a low intensity UV-C can be used over a long time. For air treatment, high intensity UV-C is required as the contact time with the moving air is short.