Dozens of 70 people who complained of skin irritation or respiratory distress were checked after the fire began early Wednesday afternoon and at least two were hospitalized for observation, officials said.
Lt. Jim Keightley, a State Patrol spokesman, said a half-mile area with about 100 homes - roughly 400 people - around the Wilbur-Ellis Co. complex was evacuated as an odor like that of antifreeze lingered in the foggy air.
``The chemicals are an irritant and some of them are toxic,'' said to Ken Cowdrey, Wilbur-Ellis' head of safety in Yakima. However, he said they did not include explosive chlorine, ammonium nitrate or anhydrous ammonia.
The cause was under investigation.
A hazardous materials team set up air monitors inside and outside the building as the fire smoldered through the night and early morning.
Authorities decided to let it burn itself out, rather than douse it with water that could increase the pollution risk and cleanup problems, Keightley said. A temperature inversion with fog, low clouds and a lack of wind kept the smoke from dissipating.
I-82 was closed between Sunnyside and Prosser. It reopened at about 8 a.m. Thursday.
The fire was in a 40-by-80-foot building used for storage of agricultural chemicals and fertilizers in the complex on the outskirts of this town of roughly 8,500 people about 40 miles southeast of Yakima.
Students were kept in their schools Wednesday with the ventilating systems shut down to keep out the smoke. Mayor Norm Childress said the schools would be closed Thursday.
Wilbur Ellis, based in San Francisco, is an international marketer and distributor of agricultural and industrial products.
Ramon Soto, a 48-year-old farmworker, said he came out of his Grandview mobile home Wednesday afternoon and smelled a strange odor.
``I thought my wife had burned the food,'' he laughed Wednesday night at a Red Cross shelter set up at nearby Sunnyside High School. He checked into the shelter with his wife, his daughter and her boyfriend and his 18-month-old granddaughter.
He called the evacuation an inconvenience but added ``accidents happen everywhere.''
Soto praised the pizza and sandwiches at the shelter and declared, ``I want to stay in the shelter again. They feed me real good.''
