A woman wears a mask as a precaution against the coronavirus in Honolulu on Tuesday, April 7. Caleb Jones/AP

Honolulu will begin requiring people to wear facial coverings when visiting essential businesses starting Monday.

Mayor Kirk Caldwell said the new requirement applies to businesses like grocery stores. People will not be required to have a commercially-produced mask, he said.

It's another layer of protection. It's not perfect,” Caldwell said at a news conference on Tuesday.

The mayor said the order does not apply to people working in offices that are not open to the public, although facial coverings are still recommended at those businesses. People also must cover their faces when riding public transportation.

To avoid confusion, Caldwell said there is one major exception to the rule: no one should wear a mask in a bank.

“Usually when people go into a bank with a mask, it's not a good outcome,” Caldwell said.