Mr Hancock told the Commons: “The death rate of sales and retail assistants is 75 percent higher amongst men and 60 percent higher amongst women than in the general population.”
He added: “There is also evidence that face coverings increase confidence in people to shop.”
In addition, he said those refusing to comply could be hit with a fine of £100.
Mr Hancock said: “The liability for wearing a face-covering lies with the individual.
“Should an individual without an exemption refuse to wear a face covering, a shop can refuse them entry and can call the police if people refuse to comply.
“The police have formal enforcement powers and can issue a fine.”