Towards standardized testing of air cleaners against virus aerosols

Virus particles that spread via aerosols are a serious health hazard especially for indoor environments. Source control (masks), distancing and ventilation are known to reduce the infection risks, but depending on the circumstance may not always be successfully implemented in classrooms, offices and other workplaces. In such case, air cleaners may be an additional measure to control infectious aerosols. Several international standards exist to assess the effectivity of air cleaners, but often these differ significantly in their technical approaches and are usually defined for just one or few pollutant type(s). A project was started in Germany to develop and evaluate a standard procedure for testing of air cleaners against bioaerosols in a more generalized way. In addition to testing the efficiency of virus removal or deactivation, the assessment also needs to consider the effectivity to remove other relevant pollutants, the occurrence of possible by-products and other parameters like operating noise.