Workers at an Ozaukee County cheese plant were evacuated after an employee apparently mixed the wrong chemicals.
It happened around 10 p.m. last night at the Cedar Valley Cheese Plant in Fredonia -- that's about 30 miles north of Milwaukee.
Officers say an employee added the wrong chemical in a sterilization process.
That caused a heavy odor to fill part of the plant.
A hazardous materials team was on the scene for a couple of hours.
Deputies say no one was hurt.