For the second time this semester, an unidentified white substance found in a campus building has been tested and proven not harmful.

The latest incident occurred on Tuesday, as a pile of white powder was spotted in the second floor of McDonnell Douglas Hall. Cleaning staff found the powder on a wooden alcove on the west side of the floor.

According to Department of Public Safety Director Jack Titone, the University Chemical Response Team sent samples of the powder to a private lab, where it was determined that the substance was not biological.

Titone said that the City Emergency Management Agency was also present to observe these testing procedures and to perform a threat analysis on the situation. “Once they determined it not to be a credible threat, the [Chemical Response Team] took samples to be tested,” Titone said.

Titone speculated that the substance was most likely cream or sugar left behind from students who may have used the alcove as a sitting area.

Earlier this semester, another white substance that turned out to be mortar residue was found in Pius XII Memorial Library.