GRANDVIEW, Wash. (AP) -- About 100 homes and businesses remained evacuated Thursday as a chemical fire continued to burn in south-central Washington, sending potentially harmful smoke into the air.
State and federal authorities were monitoring air quality near the Wilbur-Ellis Co., an agricultural chemical and fertilizer retail operation where the fire broke out Wednesday afternoon.
Authorities had not detected dangerous levels of toxic chemicals in the air beyond 100 feet from the building, but about 400 nearby residents remained out of their homes Thursday night as a precaution, said Mark MacIntyre, a spokesman for the U.S. Environmental Protection Agency. About 40 of them were staying at a shelter.
``They want to be cautious, because the nature of the fire is still questionable,'' MacIntyre said.
Dozens of people have been checked at area hospitals after complaining of skin irritation or respiratory problems.
The fire was in a 40-by-80-foot building used to store agricultural chemicals and fertilizers in the complex, which includes a warehouse and office building on the outskirts of this town of roughly 8,500 people about 40 miles southeast of Yakima.
Authorities decided to let the fire burn itself out, saying that dousing it with water could increase the pollution risk and cleanup problems.
Workers induced the fire to burn faster Thursday by using a backhoe to tear the roof off the building and punch holes in its walls. Officials wanted the fire to consume the available fuel so they could get a closer look at the building Friday morning, MacIntyre said.
A nearby section of Interstate 82 reopened Thursday morning after being closed for about 18 hours. The Grandview School District, which serves about 3,000 students, was closed Thursday as a precaution and was to remain closed Friday, MacIntyre said.
The cause of the fire remained under investigation.