Performance of Fabrics for Home-Made Masks Against the Spread of Respiratory Infections Through Droplets: A Quantitative Mechanistic Study

Abstract

AbstractRespiratory infections may spread through droplets and aerosols released by infected individuals coughing, sneezing, or speaking. In the case of Coronavirus Disease 2019 (COVID-19), spread can occur from symptomatic, pre-symptomatic, and asymptomatic persons. Given the limited supply of professional face masks and respirators, the U.S. Centers for Disease Control and Prevention (CDC) has recommended home-made cloth face coverings for use by the general public in areas of significant community-based transmission. There is, however, little information on the effectiveness of cloth face coverings in reducing droplet dissemination. Here, we ascertained the performance of 11 household fabrics at blocking high-velocity droplets, using a commercial medical mask as a benchmark. We also assessed their breathability (air permeability), texture, fiber composition, and water absorption properties. We found that droplet blocking efficiency anti-correlates with breathability; less breathable fabrics being more effective in blocking. However, materials with high breathability are desirable for comfort and to reduce airflow through gaps between the mask and face. Our measurements indicate that 2 or 3 layers of highly permeable fabric, such as T-shirt cloth, may block droplets with an efficacy similar to that of medical masks, while still maintaining comparable breathability. Overall, our study suggests that cloth face coverings, especially with multiple layers, may help reduce droplet transmission of respiratory infections. Furthermore, face coverings made from biodegradable fabrics such as cotton allow washing and reusing, and can help reduce the adverse environmental effects of widespread use of commercial disposable and non-biodegradable facemasks.