CHICAGO, June 15 (Xinhua) -- The massive fire at the chemical plant in Rockton in the northern part of U.S. Midwest state Illinois continued for the second day on Tuesday, with mandatory evacuation within one-mile radius remaining and advisory for anyone outside within 3 miles to wear masks added.
The Chemtool factory exploded on Monday morning, sparking fires and shooting black smoke and flames high into the air.
Chemtool, which produces industrial lubricants, said all of its 70 employees were able to evacuate without injury.
At a press conference on Tuesday, Rockton Fire Chief Kirk Wilson said a firefighter was transported to the hospital for minor injuries.
Potentially toxic compounds like lead, nitrogen and sulfuric acids only fueled the flames and that drowning the fire with water simply isn't an option, local media quoted fire officials as saying.
Firefighters have dug trenches along the west side of Chemtool to act as a block of any type of residual material that might go into the Rock River, Wilson said.
Air testing showed no danger at ground level, the state officials said, promising to keep monitoring the situation together with U.S. Environmental Protection Agency (EPA).
Bill Snyder, vice president of operations at Lubrizol, Chemtool's parent company, issued an apology Tuesday morning.