The study carried out by HeX Lab and other laboratories compares the methods used to test the filtration efficiency of medical masks, in the context of COVID-19.

During this period, bacterial filtration efficiency (BFE) measurements were carried out to assess the effectiveness of medical masks in preventing the spread of bioaerosols. These simple-to-perform measurements raise a number of scientific questions.

This inter-laboratory study compares the Bacterial Filtration Efficiency (BFE) test with the Particulate Air Filtration Efficiency (PFE) test. It was carried out on six commercial surgical masks with 3 µm particles. Fractional filtration efficiencies were measured and compared to explain the differences.

This study, carried out with the aim of establishing an overview and observing the differences between the two test methods, also enabled recommendations to be made for improving the EN14683:2019+AC standard.