A medical mask is a loose fitting and disposable device that forms a physical barrier between (a) the wearer’s mouth and nose, and (b) potential contaminants in the wearer’s immediate environment. It is also called a medical face mask. On a practical level, these masks will protect the wearer from large viral or bacterial particles. These may be in droplets, sprays, splashes and splatter.
They may also provide protection to others in the vicinity of the wearer from his or her saliva and respiratory expulsions.
However, a medical face mask will not protect the user from small viral or biological particles. These may be present in the sneezes or coughs of others in the wearer’s immediate environment. They are therefore generally less effective than respirators. Furthermore, they do not form a close fitting seal against the face as do most respirators.
A medical face mask is particularly recommended for patients suffering from infectious respiratory illnesses (such as COVID-19) when KN95 or N95 respirators are not available. They are also particularly important PPE for for those caring for these patients (again, when N95 or KN95 respirators are not available).
A medical mask is required for health care works such as a physiotherapist or massage therapist. This is due to their close proximity to the patients they are treating. In most cases, these masks will need to be at the ASTM Level 2 standard (see below).
Testers usually evaluate the medical masks in this section for conformance with standards set by the ASTM. This organization was formerly known as the American Society for Testing & Materials.