When considering whether COVID-19 can be filtered out using ventilation system filters, the first point to bear in mind is the size of viruses. Viruses are significantly smaller than bacteria, which are relatively large at 1-10 µm and can therefore be separated out efficiently by ePM1 fine dust filters. The coronavirus measures approximately 0.16 µm. Having said that, viruses are generally attached to aerosols or dust particles. Transmission is primarily via droplets. Droplets that people produce are 0.5 to approx. 15µm in size. From other viruses it is known that a 1µm-droplet can contain a sufficient virus concentration to trigger an infection.
ePM1 filters separate out particles and aerosols, i.e. including droplets, down to a size of 1µm, depending on the separation efficiency. With higher separation efficiency, more of these droplets are separated out and thus remain in the filter medium. When filters are replaced during servicing, personal protective equipment (PPE) should therefore always be worn. This is true irrespective of the current COVID-19 pandemic, as it is generally unknown what substances have been collected in the filter.
