Wearing a face covering is a public health measure designed to capture respiratory droplets from the wearer, who may or may not yet have symptoms of COVID-19, to prevent onward transmission.¹Three quarters of countries across the world currently recommend or mandate their use.² After initially advising against face coverings, the US Centres for Disease Control and Prevention, the World Health Organisation and the UK Government all now recommend their use.^1,3,4 Guidelines on public use of face coverings draw on the principles of infection control to recommend how to make or obtain, use and clean them. Such guidelines are often presented alongside guidelines intended for healthcare facilities. In this article, we contrast medical and sociocultural narratives for face coverings and argue for more explicit engagement with the latter when promoting uptake.

Terminology varies but can broadly be divided into medical masks (which are regulated by manufacturing specifications and include surgical masks), non-medical masks (which include cloth masks and other fabric face coverings), filtering facepiece respirators (including FFP2 or N95 respirators) and face shields (usually made of Perspex). Recommendations on what members of the public should use differs between countries and is influenced by local norms and country-level supply of personal protective equipment for health workers. As COVID-19 spread, China and South Korea rapidly increased production of medical masks, whereas Czechia and Thailand have been early proponents of using cloth masks to conserve supplies of medical masks.² In 1897, a ‘medical mask’ typically consisted of some layers of gauze tied with string, and later became four-ply cotton muslin; in most modern healthcare settings such masks are disposable and made of layers of paper and waterproof backing. ⁵ In this paper we use the term ‘face covering’ to include the full range of materials people adapt and use to cover their mouth and nose to prevent the spread of SARS-CoV-2. This include medical and non-medical masks, but also pieces of clothing. We do not consider Perspex face shields in this article because they are not currently advised for primary respiratory protection or for source control and also not respirators as they are recommended for use by health workers.¹