The woman was pushing her housekeeping cart on the 6th floor of the hotel, near 100 South and West Temple, when the cart bumped a can of bear spray that had been left on the floor of the hall.
The can sprayed when it was struck, shooting out a substance that "is like pepper spray, only 10 times stronger," said Salt Lake City battallion fire chief Clair Baldwin. Investigators were trying to determine why the can was left in the hallway.
The woman was unable to open her eyes after being exposed to the spray, so she was taken to a hospital, Baldwin said. All guests at the hotel were evacuated for about a half hour while crews ventilated the building.
No one else required medical care, Baldwin said.