Police and fire officials evacuated the Chevron Science Center Saturday night after a… Police and fire officials evacuated the Chevron Science Center Saturday night after a staff member reported finding a suspicious substance there.

The incident began at approximately 9:25 p.m., according to Pitt spokesman Robert Hill, when the staff member found the substance in a refrigerator on the 12th floor of the building.

Though the substance turned out to be harmless, Hill said there was concern that it could be tetrahydrofuron, a chemical solvent that can damage mucous membranes.