Face masks during the COVID-19 pandemic

During the COVID-19 pandemic, face masks such as surgical masks and cloth masks, have been employed as a public and personal health control measure against the spread of SARS-CoV-2. Their use is primarily intended as source control to limit transmission of the virus to others in community and healthcare settings as well as some degree of personal protection to prevent infection.

The use of face masks or coverings by the general public has been recommended by health officials to minimize the risk of transmissions, with authorities either requiring their use in certain settings, such as on public transport and in shops, or universally in public. Health officials have advised that medical-grade face masks, such as respirators, should be prioritized for use by healthcare workers in view of critical shortages. They recommend cloth masks for the general public.[1][2]

Early in the pandemic, public health messaging about masking often offered inconsistent and conflicting statements, often dismissive, which led to public confusion and subsequent scrutiny. The recommendations have changed as the body of scientific knowledge evolved.[3] One early recommendation was that only symptomatic individuals should wear masks, though evidence suggested asymptomatic transmission. This was revised to also include individuals without symptoms. About 95% of the world's population live in countries that recommend or mandate the use of masks in public during the pandemic.[4]

There were shortages of masks, leading to use of uncertified and substandard masks with performance inferior to better types.[5]

Different types of face masks have been recommended throughout the COVID-19 pandemic including:

cloth face masks

medical or surgical masks

face-sealing filtering facepiece masks with respirator certifications such as N95 and N99 respirators, and FFP respirators

uncertified face-sealing dust masks

other respirators, including elastomeric respirators, some of which may also be considered filtering facepieces.

Transparent face shields, medical goggles, and other types of personal protective equipment (PPE) are sometimes used in conjunction with face masks.