Cloth face mask

Guidance from the U.S. Centers for Disease Control and Prevention on using and making cloth masks during the COVID-19 pandemic[1]

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.[2] Like surgical masks, and unlike respirators, cloth face masks do not provide a seal around the face.[3]

In healthcare settings, they are used on sick patients as source control to reduce disease transmission through respiratory droplets, and by healthcare workers when surgical masks and respirators are unavailable. Cloth face masks are only recommended for use by healthcare workers as a last resort if supplies of surgical masks and respirators are exhausted.[3] They are also used by the general public in household and community settings as perceived protection against both infectious diseases and particulate air pollution and to contain the wearer's exhaled virus laden droplets.[3][4]

Several types of cloth face masks are available commercially, especially in Asia.[4] Homemade masks can also be improvised using bandanas,[1] T-shirts,[1][2] handkerchiefs,[2] scarves,[2] or towels.[5]

Two French cloth masks certified by AFNOR. The white mask is made of polypropylene and the black one is made of cotton.

The World Health Organization (WHO) recommends that cloth face masks should be worn in public where social distancing is not possible to help stop the spread of coronavirus. It notes that wearing a cloth face mask is just one of a range of tools that can be used to reduce the risk of transmission.[6] The US Center for Disease Control, along with Johns Hopkins University School of Medicine, The Mayo Clinic, and Cleveland Clinic all concur with this recommendation.[7][8][9][10] The World Health Organization also recommended that those aged over 60 years old or with underlying health risks require more protection and should wear medical masks in areas where there is community transmission.[6]

The World Health Organization recommends using masks with at least three layers of different materials. Two spunbond polypropylene layers are also believed to offer adequate filtration and breathability.[11] When producing cloth face masks, two parameters should be considered: filtration efficiency of the material and breathability. The filter quality factor known as "Q" is commonly used as an integrated filter quality indicator. It is a function of filtration efficiency and breathability, with higher values indicating better performance. Experts recommend Q-factor of three or higher.[11]

Cloth face masks can be used for source control to reduce disease transmission arising from the wearer's respiratory droplets, but are not considered personal protective equipment for the wearer[12][13] as they typically have very low filter efficiency.[14][15] There are no standards or regulation for self-made cloth face masks.[15]

As of 2015, there had been no randomized clinical trials or guidance on the use of reusable cloth face masks.[3][5] Most research had been performed in the early 20th century, before disposable surgical masks became prevalent. One 2010 study found that 40–90% of particles in the 20–1000 nm range penetrated a cloth mask and other fabric materials.[14] The performance of cloth face masks varies greatly with the shape, fit, and type of fabric,[4] as well as the fabric fineness and number of layers.[5] As of 2006, no cloth face masks had been cleared by the U.S. Food and Drug Administration for use as surgical masks.[2]

The primary role of masks worn by the general public is to "stop those who are already infected broadcasting the virus into the air around them."[16] This is of particular importance with the COVID-19 epidemic, as silent transmission seems to be a key feature of its rapid spread. For example, of the people on board the Diamond Princess cruise ship, 634 people were found to be infected—52% had no symptoms at the time of testing, including 18% who never developed symptoms.[17]

An experiment carried out in 2013 by Public Health England, that country's health-protection agency, found that a commercially made surgical mask filtered 90% of virus particles from the air coughed out by participants, a vacuum cleaner bag filtered out 86%, a tea towel blocked 72% and a cotton t-shirt 51%—though fitting any diy mask properly and ensuring a good seal around the mouth and nose is crucial.[18][16] The use of common fabrics in making face masks has been tested.[19][20][21][22]

During the 1918 flu pandemic, a streetcar conductor in Seattle refuses a person who attempts to board without wearing a mask.

The first recorded use of a cloth face mask involved the French surgeon Paul Berger during an 1897 operation in Paris.[23] Masks came into use to protect against infectious diseases in the early 20th century.[3][5] A design by Wu Lien-teh, who worked for the Chinese Imperial Court during the 1910–11 Manchurian pneumonic plague outbreak, was the first that protected users from bacteria in empirical testing; it inspired masks used during the 1918 flu pandemic.[24] The first study of mask use by healthcare workers took place in 1918.[3][5] In the 1940s, face masks made from cheesecloth were used to protect nurses from tuberculosis.[25]

Cloth masks were largely supplanted by modern surgical masks made of nonwoven fabric in the 1960s,[2][5] although their use continued in developing countries.[3] They were used in Asia during the 2002–2004 SARS outbreak, and in West Africa during the 2013–2016 Ebola epidemic.[3]

COVID-19 pandemic

Main article: Face masks during the COVID-19 pandemic

Rhode Island National Guardsmen sew face masks during the COVID-19 pandemic, April 6, 2020.

During the COVID-19 pandemic, multiple countries recommended the use of cloth masks to reduce the spread of the virus.

On June 5, WHO has changed its advice on face masks, recommending that fabric masks should be worn by general public where social distancing is not possible (e.g., on public transport, in shops or in other confined or crowded environments).[11][26]