An infectious disease expert from Nottingham has raised issues with the exemption categories for wearing face masks.
It comes as news that shoppers will soon have to wear face coverings was met with concern.
From July 24, you must have your nose and mouth covered when you go shopping or risk a £100 fine - reduced to £50 if it is paid within 14 days.
This does not have to be a face mask - the Government has outlined it can be a scarf, bandanna or other fabric items that can cover the nose and mouth.
However, similar to when face coverings became mandatory on public transport, there are exemptions which include people with health conditions, disabilities or due to age.
Prime Minister Boris Johnson has faced a backlash over the new rule from Conservative Party members and former minister Sir Desmond Swayne, who claimed it goes against their libertarian values and there is insufficient evidence the measure has meaningful health benefits.
The Scientific Advisory Group for Emergencies (Sage) has also said incorrect use of coverings such as putting them on incorrectly, touching the face more than normal and reusing dirty ones could increase the spread of infection.
Keith Neal, emeritus professor of the epidemiology of infectious diseases at the University of Nottingham, said the lack of strong evidence of the effectiveness of face coverings should not be considered a problem.
He added: "The evidence is accumulating that they have a part to play in reducing transmission and also in protecting the wearer.
"Issues may arise on exemptions apart from age as people can claim to meet one of the exemption categories without obvious evidence.
"Exemptions like for anxiety can easily be used as an excuse given the apparent reluctance from too many people."
