A medical mask should be two or three layers thick. Personal protective equipment of this thickness was called effective by a senior British health official and physician Susan Hopkins, according to the Daily Mail.
She noted that the more layers on the mask, the more reliable it will protect against the spread of the virus. Hopkins also clarified that the British authorities advise wearing one multi-layer mask, and not two worn on top of each other, as is often done in the United States.
Since July 2020, masks in Britain must be worn in all enclosed spaces: in transport, shops and restaurants. An exception is granted only for children under 11 years of age and people with special medical conditions.
Earlier, the Czech authorities issued a decree according to which residents of the republic from February 25 in crowded places must wear two masks at once. The country’s health minister Jan Blatny explained that instead of two masks, it will be possible to wear respirators without an exhalation valve, which have the degree of protection of FFP2 or KN95.