A cloth face mask is a mask made of common textiles, usually cotton, worn over the mouth and nose. When more effective masks are not available, and when physical distancing is impossible, cloth face masks are recommended by public health agencies for disease "source control" in epidemic situations to protect others from virus laden droplets in infected mask wearers' breath, coughs, and sneezes. Because they are less effective than N95 masks, surgical masks, or physical distancing in protecting the wearer against viruses, they are not considered to be personal protective equipment by public health agencies. They are used by the general public in household and community settings as protection against both infectious diseases and particulate air pollution. Cloth face masks were routinely used by healthcare workers starting from the late 19th century until the mid 20th century. In the 1960s they fell out of use in the developed world in favor of disposable surgical masks with an electret (electrically charged) filter material, but cloth masks persisted in developing countries. During the COVID-19 pandemic, their use in developed countries was revived due to shortages, as well as for environmental concerns and practicality. Launderable cloth electret filters were also being developed. Face masks during the COVID-19 pandemic Prior to the COVID-19 pandemic, reusable cloth face masks were predominantly used by healthcare workers in developing countries and were especially prominent in Asia. Cloth face masks contrast with surgical masks and respirators such as N95 masks, which are made of nonwoven fabric formed through a melt blowing process, and are regulated for their effectiveness based upon efficiency of minimum particle size filtered and/or maximum penetrating particle (MPP) size, along with other criteria such as outer splash/spray protection, inner splash/spray absorption, contaminant accumulation and shedding, air flow, and inflammability.