Air purifiers against Covid-19

This is the opinion of VITO on 09/11/2020.

Air purification can be an additional measure to reduce the risk of Covid-19 virus transmission in the indoor environment. However, air purification cannot be used as a substitute for ventilation, but can further reduce the risk of airborne virus transmission in rooms that are already ventilated, in addition to measures such as social distancing, mask use, etc.  

Although in theory any technique that removes aerosols or particles from the air can also remove SARS-CoV-2 from the air, for the time being, according to the current scientific literature, only HEPA air filtration and UV light-based methods have been sufficiently demonstrated to be effective. For other techniques, there is only limited evidence of their effectiveness against removal of SARS-CoV-2 or the formation of undesirable substances can lead to health effects such as respiratory and skin irritations.  

Always ask the supplier, also for methods based on HEPA air filtration and UV-light, for independent laboratory and field validation reports proving the effectiveness for SARS-CoV-2 reduction and taking into account by-products possibly emitted by the device.  

In addition, there are a number of other points to consider when using an air purifier:

• Place the device in the centre of the room, close to the people present;
• Use the device in accordance with the manufacturer's guidelines;
• ensure proper maintenance of the unit;
• The volume of air that the unit cleans per hour must be adapted to the volume of the room, the activities (as a function of aerosol production) that take place in the room, the number of people in the room and the efficiency of air purification;
• take care with air flows caused by the device where air is blown directly from one person to another.  

Please refer to the full advice: pdf fileAirborne transmission restriction devices for Covid-19 (759 kB)