University of Colorado police and Boulder firefighters responded to a report of a fire in the Molecular Cellular and Developmental Biology Building on the University of Colorado campus on Tuesday afternoon.

CU spokesman Peter Caughey said CU police received a report of a fire at 3:18 p.m. Tuesday.

Boulder Fire Duty Battalion Chief Mark Johnson said the incident turned out to be a piece of plastic that melted because it was too close to an autoclave, a machine that uses pressurized steam to sterlize instruments. It does not appear it actually caught fire, he said, though it generated a noxious odor of burning plastic.

Caughey said he had reports there was a small fire that was contained to room A106. It was extinguished with a fire extinguisher.

The building was evacuated, but the no one was injured, Caughey said.

Damage from the fire was minimal, Caughey said.