Shelter-in-place order issued after Colo. steel mill fire produces thick smoke

April 6 (UPI) -- No hazardous substances were involved in a fire at a steel mill in Pueblo, Colo., that produced thick clouds of smoke and caused officials to issue a shelter in place order, the Environmental Protection Agency says.

The shelter in place order was lifted Saturday morning and the EPA later gave the all-clear.

The agency said told KKTV-TV its staff arrived at the Evraz North America Inc. steel mill in Pueblo on Friday to conduct air monitoring in the wake of a sprawling smoke plume that engulfed the surrounding neighborhoods.

The fire broke out Friday afternoon in an area of the mill primarily used for staging and storage, sending thick black smoke into the air and leading the Pueblo Department of Public Health and Environment to issue an air quality alert.

First responders were immediately concerned about the possibility of toxic substances in the smoke.

"First responders determined that there were no hazardous substances involved in the fire," the agency said in the statement. "Out of an abundance of caution, EPA will continue to conduct air monitoring in the surrounding area. EPA will provide the local health department with the monitoring data."

The fire was 80% contained by around 5:30 p.m. MDT, after scorching through 82 acres.

More than 20 homes were put on evacuation alerts in case the fire spread across a dry grass area.

No injuries or deaths were reported as a result of the fire.