IISc puts face masks through rigorous testing

Since the start of the COVID-19 pandemic, the use of homemade face masks has been advised as a possible substitute for commercially available surgical or N95 masks. Researchers at the Indian Institute of Science (IISc) in Bengaluru have carried out a detailed study on the fate of a large-sized surrogate cough droplet impinging at different velocities (corresponding to mild to severe coughs) on various locally procured cloth fabrics (stole, handkerchief, cotton towel, and surgical masks), specifically those which are convenient for people to use every day. Based on their findings, the researchers recommend using a cotton towel (with at least three layers) as a face covering if the person cannot use an N95 or a surgical mask. Masks with three or more layers are ideally recommended since they can suppress aerosolisation significantly. The team also analysed the effect of washing on mask effectiveness, and results show a negligible influence of washing on mask efficacy up to 70 wash cycles.