Employers can require employees to wear a face mask at work. If your business is going to require it, you should provide the masks or pay for them.
Currently, it is a best practice to require vendors, guests, customers and others entering your workplace to wear one. Be sure to train employees in the use and care of masks including explicit instructions on when the mask is necessary, how to properly put on, take off, adjust, and wear the mask; the limitations of the mask; and the proper care, maintenance, useful life and disposal, including replacing worn or damaged masks.
– Stephanie Quincy, Quarles & Brady LLP