Filtration efficiency of a large set of COVID-19 face masks commonly used in Brazil

The use of face masks is mandatory in public places many countries to slow the spread COVID-19 pandemic. In developing countries, homemade with varying techniques and fabrics are used on streets. On these fabric masks, protection against SARS-CoV-2 varies significantly. most common mask types N95, surgical nonwoven cotton masks. performance 227 different Brazil was evaluated quantify their breathability filtration efficiency (FE) for airborne particles. FE values were measured using NaCl aerosol particles sized from 60 300 nm at nm, minimum efficiency. differential pressure drop over FEmin calculate Quality Factor (QF). N95 showed highest FE60-300, around 0.98, a QF 13.2 KPa?1, considered reference evaluating performance. Surgical have an FE60-300 0.89, good 15.9 KPa?1. Nonwoven average 0.78, excellent 24.9 can be regarded as best material commonly fabrics, significant variability ranging low 0.20–0.60, 1.4 Masks always reduce droplets aerosols emitted by symptomatic asymptomatic persons, reducing contamination.Copyright © 2021 American Association Aerosol Research