Filtration efficiency of face masks and veils as protective measures during COVID-19 pandemic

Wearing face masks have been implemented as a public and personal health control measure against the spread of coronavirus disease (COVID-19). However, protection level nonmedical masks, such women veils, is still uncertain. This study aimed to assess filtration efficiency (FE; percentage particles retained by mask) different types medical (either sealed or unsealed, single doubled), non-medical (cloth masks) veils. FE was evaluated using an in-house 3D-printed air duct connected Aerotrak particle counter with capability counting sizes 0.3, 0.5, 0.7, 1, 2 5 μm. A set 10 earloop surgical masks,10 tie-on 3 triple-layers reusable cloth (short, medium long) traditional veils were included in study. The unsealed showed intermediate (36.54-80.58%), no observed differences between doubled masks. For each mask type, mean values (FE≥99.16%) significantly higher (P<0.001) than ones (FE≤80.58%). No significant difference either (FE=23.19-75.35%, P=0.26) (FE=19.10- 70.68%, P=0.14). mockup experiment that wearing under veil improve (33.73-79.18%; P<0.001). We conclude besides ensure optimal experimental conditions, comparable performance acceptable at μm size, which most relevant size associated COVID-19 infectious droplets. improves compared alone.