Kansas University’s Malott Hall reopened about 4:45 p.m. Friday, several hours after a chemical spill caused students and staff to evacuate the building.

A small amount of ammonium hydroxide spilled in a prep lab on the first floor of the seven-story building. No one was injured in the spill, said Chris Keary, KU assistant police chief.

About 2 p.m., a female staff member was returning a 2.5 liter bottle of ammonium hydroxide to a shelf when it fell and broke. Emergency crews evacuated the entire building, which houses the physics and chemistry departments.

Hazmat crews arrived on scene to decontaminate the spill, which took place in an older part of the building that’s located at 1251 Wescoe Hall Drive. KU’s environmental, health and safety department is continuing to clean up the spill.

While the lab remains closed, the rest of the building has reopened.