A large acid spill occurred Friday in the Engineering Research Building on campus, forcing it to be evacuated by the Madison Fire Department.

The spill occurred around 3:48 p.m. on the 12th floor of the building, located at 1500 Engineering Dr., across from Engineering Hall. No one was injured in the spill.

Workers in the building helped contain the spill by closing doors around the affected areas.

People inside the building also heard a loud “pop” sound around the same time as the spill, though it is uncertain if the two events are connected, according to Fire Department spokesperson Bernadette Galvez.

The spill also produced a yellow haze on the 12th floor, according to Galvez. “This is a good thing we got everybody out on time,” she said.

A Hazardous Material team found that several half-gallon containers of Acetic acid and Ammonia were near the area of the spill, according to a Madison Fire Department report. Smaller containers of Nitric acid, Hydrofluoric acid and Hydrochloric acid were also part of the spill.

UW-Madison Safety teams cleaned up the spill Friday afternoon. Students and staff were allowed to return to the building later in the day.