Filtration mechanisms and manufacturing methods of face masks: An overview

Face masks are loose-fitting masks that cover the nose and mouth and have ear ties at the back of the head whereas respirators are tight-fitting face covering devices which filter the air during inhalation and exhalation. Guidelines issued by the US Centers for Disease Control and Prevention (CDC) regarding proper design, filtration process and wearing should be followed. The mask equipment provides protection against the infections caused by particulate matters (PM), especially PM2.5, and biological pathogens such as bacteria and viruses. Although face masks offer benefits to a greater extent, it is not recommended to wear them for a long period of time. As N95 masks closely fit with the face, it may result in negative impact on respiratory and dermal mechanisms of human thermoregulation. In this article, currently available face masks including cloth masks, their filtration mechanisms, manufacturing methods and decontamination methods are reviewed for the purpose of helping with the coronavirus pandemic (COVID-19).