The Madison Fire Department responded to a report of a chemical leak at a building on the UW Campus Thursday afternoon
UW Police department spokesperson Marc Lovicott said firefighters were called to a report of a problem at Engineering Hall around 12:15 p.m. Thursday.
Fire officials arrived shortly afterwards and evacuated Engineering Hall when they arrived.
According to Lovicott, some students were cleaning out a filter when the accidentally spilled some arsine, which is a highly toxic, flammable chemical.
Firefighters quickly cleaned up the spill before letting people back in the building.
Engineering Drive was shut down for a while, but the building and the street were reopened by 1 p.m.