Smoke or steam coming from a large trash bin prompted the evacuation of workers Tuesday at the 21st Century Environmental Management Inc. plant just east of Fernley.
A hazardous materials team was called to the facility between Interstate-80 and U.S. 50A while dirt and water were dumped on the material.
The team determined that the cloud apparently was steam that was visible in the cold, damp air. Their tests showed no signs of any harmful fumes and workers were allowed to return to the plant.
Health department officials were called in to make their own assessment.
The plant, built in 1986, reclaims metals from various types of batteries.