A student studies outside the newly completed Jeong H. Kim Engineering Building, the site of another chemical fire Monday.

A throng of police cars, ambulances and fire trucks blocked the entrance of Paint Branch Drive Tuesday afternoon after a chemical spill ignited a fire in the Jeong H. Kim Engineering Building — the third chemical accident within two months.

At 4:10 p.m., firefighters, police and investigators from the Department of Environmental Safety responded to a fire alarm in the engineering research building. Two students were conducting a gravity experiment in a room on the ground floor. When a sodium metal was being transferred, it leaked from the drum that was containing it and was ignited because of air exposure, University Police spokeswoman Maj. Cathy Atwell said.

She said police reports didn’t detail exactly what type of sodium metal it was.

Atwell said there were no injuries, but police evacuated everyone from the building. The building was closed overnight and reopened Wednesday morning.

The extent of property damage was uncertain, Atwell said, but was limited to the ground floor.

She said the Department of Environmental Safety is continuing to investigate the spill.

The engineering building is located near Paint Branch Drive, between the AV Williams Building and the Chemical and Nuclear Engineering Building. Construction on the $56 million building was completed this past spring, and it is the new home of the engineering school.

This is the third chemical fire within two months. In early June, an explosion involving nitric acid in Glenn L. Martin Hall burned a student’s face and upper body, leaving him with first- and second-degree burns.

Later that month, another chemical explosion sparked in the chemistry building when sodium hydride came into contact with water. No injuries were reported in that accident.