SAUK CITY, Wis. -- Authorities evacuated scores of workers from a business in Sauk City Wednesday afternoon because of a chemical spill, and three dozen people were taken to the hospital as a precaution.

The incident occurred at an equipment room at Unity Health Insurance, in the 800 block of Carolina Street, at about 1 p.m.

Sauk Prairie Police Chief Gerald Strunz said the spill involved a solution of chlorine bromine that's used as a cleaning agent in air-cooling towers.

The chief said about 140 employees were evacuated. The 36 taken to Sauk Prairie Memorial Hospital & Clinics had minor symptoms such as watery eyes and scratchy throats. No serious injuries were reported.

"Exposure to this type of chemical manifests itself by somebody experiencing itchy, watery eyes, maybe a chemical taste in your mouth, sore throat, itchy throat -- things like that," Strunz said.

Workers described a strong swimming pool-like smell, which came from the solution of chlorine bromine that spilled in an equipment room.

"I was walking up the stairs. I was at lunch, and a bunch of people (said), 'Oh my gosh, you're pregnant -- you got to get out of here.' So I grabbed my cup and purse and walked out the door and I sat on the picnic tables until they told us to get away from the building further," said Megan Wopat, an evacuated worker.

EMS units checked each employee for any adverse reactions to the chemical exposure. All of the workers taken to a local hospital as a precaution have been released.

"The EMS on scene identified that people seemed to have minor symptoms and it's a sort of thing that we like to monitor over time. There's always a chance that what may initially look minor may develop into more major symptoms, so people came and were observed and as we felt that they were improving, we were comfortable letting them go then," said Miles Morgan, an emergency physician.

Later Wednesday afternoon, workers were finally able to get to their cars.

The chemical in question, just a gallon's worth of a chlorine-bromine solution, has safely been removed, and the building is set to reopen Thursday.

The fire department has been ventilating the building.

The cause remains under investigation.

Just two days ago, EMS crews and health officials took part in a mock chemical emergency drill, which tested the very skills they used Wednesday.