Disposable face masks are devices used to cover the mouth and nose. They serve as a barrier for contaminants from getting released from the mouth of a sick person and spread to the environment or to be inhaled by people in the public.

They are considered to be effective when the infected person wearing it would not have direct contact to people around him. The case is different with healthcare workers who are vulnerable to be infected as they are frequently exposed to diseases. People with medical conditions such as emphysema or asthma are advised to consult with a physician before wearing a mask as it might worsen their breathing condition.