Vapor leak closes I-90

MOSES LAKE – A cloud of chemicals that can irritate the nose and throat was released from a silicon plant Friday morning, prompting 11 people to seek medical attention, officials from REC Silicon Inc. in Moses Lake said.

All of the people were treated and released, the company said in a news release.

Roads around the plant, including Interstate 90, were briefly closed, and people working around the plant were ordered to stay indoors and close doors and windows, the Grant County Sheriff’s Office said.

Warning alarms at the plant went off at 7:05 a.m., and a chemical cloud appeared shortly after that, drifting to the south. The cloud contained silicon tetrachloride and trichlorosilane, which can react with moisture to become an irritant to membranes in the nose and throat, the company said.

No ground-level concentrations of the chemicals were detected, however, and the cloud dissipated, the company said.