BACKGROUND: Face coverings constitute an important strategy for containing pandemics, such as COVID-19. Infection from airborne respiratory viruses including Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) can occur in at least three modes; tiny and/or dried aerosols (typically < 1.0 μm) generated through multiple mechanisms including talking, breathing, singing, large droplets (> 0.5 μm) generated during coughing and sneezing, and macro drops transmitted via fomites. While there is a growing number of studies looking at the performance of household materials against some of these situations, to date, there has not been any systematic characterization of household materials against all three modes. METHODS: A three-step methodology was developed and used to characterize the performance of 21 different household materials with various material compositions (e.g. cotton, polyester, polypropylene, cellulose and blends) using submicron sodium chloride aerosols, water droplets, and mucous mimicking macro droplets over an aerosol-droplet size range of ~ 20 nm to 0.6 cm. RESULTS: Except for one thousand-thread-count cotton, most single-layered materials had filtration efficiencies < 20% for sub-micron solid aerosols. However, several of these materials stopped > 80% of larger droplets, even at sneeze-velocities of up to 1700 cm/s. Three or four layers of the same material, or combination materials, would be required to stop macro droplets from permeating out or into the face covering. Such materials can also be boiled for reuse. CONCLUSION: Four layers of loosely knit or woven fabrics independent of the composition (e.g. cotton, polyester, nylon or blends) are likely to be effective source controls. One layer of tightly woven fabrics combined with multiple layers of loosely knit or woven fabrics in addition to being source controls can have sub-micron filtration efficiencies > 40% and may offer some protection to the wearer. However, the pressure drop across such fabrics can be high (> 100 Pa).
BACKGROUND: Face coverings constitute an important strategy for containing pandemics, such as COVID-19. Infection from airborne respiratory viruses including Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) can occur in at least three modes; tiny and/or dried aerosols (typically < 1.0 μm) generated through multiple mechanisms including talking, breathing, singing, large droplets (> 0.5 μm) generated during coughing and sneezing, and macro drops transmitted via fomites. While there is a growing number of studies looking at the performance of household materials against some of these situations, to date, there has not been any systematic characterization of household materials against all three modes. METHODS: A three-step methodology was developed and used to characterize the performance of 21 different household materials with various material compositions (e.g. cotton, polyester, polypropylene, cellulose and blends) using submicron sodium chloride aerosols, water droplets, and mucous mimicking macro droplets over an aerosol-droplet size range of ~ 20 nm to 0.6 cm. RESULTS: Except for one thousand-thread-count cotton, most single-layered materials had filtration efficiencies < 20% for sub-micron solid aerosols. However, several of these materials stopped > 80% of larger droplets, even at sneeze-velocities of up to 1700 cm/s. Three or four layers of the same material, or combination materials, would be required to stop macro droplets from permeating out or into the face covering. Such materials can also be boiled for reuse. CONCLUSION: Four layers of loosely knit or woven fabrics independent of the composition (e.g. cotton, polyester, nylon or blends) are likely to be effective source controls. One layer of tightly woven fabrics combined with multiple layers of loosely knit or woven fabrics in addition to being source controls can have sub-micron filtration efficiencies > 40% and may offer some protection to the wearer. However, the pressure drop across such fabrics can be high (> 100 Pa).
Authors: William G Lindsley; Francoise M Blachere; Donald H Beezhold; Brandon F Law; Raymond C Derk; Justin M Hettick; Karen Woodfork; William T Goldsmith; James R Harris; Matthew G Duling; Brenda Boutin; Timothy Nurkiewicz; Theresa Boots; Jayme Coyle; John D Noti Journal: Aerosol Sci Technol Date: 2021-06-14 Impact factor: 4.809
Authors: Mahshid Ataei; Farshad M Shirazi; Samaneh Nakhaee; Mohammad Abdollahi; Omid Mehrpour Journal: Environ Sci Pollut Res Int Date: 2021-10-23 Impact factor: 4.223
Authors: Ian A Carr; Gavin D'Souza; Ming Xu; Shailesh Ozarkar; Daniel Porter; Marc Horner; Prasanna Hariharan Journal: Ann Biomed Eng Date: 2022-07-28 Impact factor: 4.219
Authors: Sandra Schorderet Weber; Xavier Bulliard; Rosy Bonfante; Yang Xiang; Silvia Biselli; Sandro Steiner; Samuel Constant; Raphael Pugin; Alexandra Laurent; Shoaib Majeed; Stefan Lebrun; Michele Palmieri; Andreas Hogg; Arkadiusz Kuczaj; Manuel C Peitsch; Julia Hoeng; Adrian Stan Journal: Sci Rep Date: 2022-10-11 Impact factor: 4.996
Authors: William G Lindsley; Francoise M Blachere; Donald H Beezhold; Brandon F Law; Raymond C Derk; Justin M Hettick; Karen Woodfork; William T Goldsmith; James R Harris; Matthew G Duling; Brenda Boutin; Timothy Nurkiewicz; John D Noti Journal: medRxiv Date: 2021-02-19