Máscarasdo Bem: An analysis of face-mask performance from a volunteer mask-making initiative in Ribeirão Preto, Brazil

OBJECTIVES: This study examines the response of a group of volunteers in Ribeirão Preto, Brazil, as the city faced an unprecedented demand for face masks during the onset of the COVID-19 crisis in 2020. The performance of artisanal-produced masks was compared with industry equivalents. STUDY DESIGN: Case report with comparative testing. METHODS: A comparison was made between two parallel projects that produced single-use masks for healthcare workers and reusable masks for the community. Mask samples were tested for filtration efficiency (FE) and breathability (pressure drop). RESULTS: Results for FE averaged 40–60% for healthcare masks and 10% for community masks; both types of masks were tested for particle sizes of 0.3 ​μm. CONCLUSIONS: While performance was inferior to standard comparators, the masks investigated in this study afforded a level of protection in the absence of alternatives, especially in non-aerosol generating contexts. The findings of this study are useful for communities with limited resources in other developing countries. In addition, insights can be gained from the experiences in Ribeirão Preto in terms of how to respond to future health emergencies.