The East Central College Health and Science building was evacuated Monday afternoon after the report of a gas odor, authorities said.

Union Fire Protection District Chief Russ Hamilton said there was a report of an unknown odor about 1:30 p.m.

He said Missouri Natural Gas had been conducting work on a pump in the building, which could have caused the odor.

Hamilton noted that there also were two chemistry classes in the building working with chemicals, which could have contributed to the smell.

Fire crews used gas detectors and received no readings on the equipment. Missouri Natural Gas returned to ECC to assist fire crews with the investigation, Hamilton said.

“We didn’t feel anybody was in any harm, and we couldn’t locate any hazard. We felt comfortable letting people reoccupy the building,” he said.