(Portland, OR) -- Intel says it's narrowing its focus in its investigation into a possible toxic exposure incident at their Hillsboro Ronler Acres campus. The company says it's looking at its manufacturing support building but that there's no evidence of hazardous material release so far. KATU reports firefighters treated 22 people at the campus Monday morning for irritation of the respiratory system. Six people were taken to a hospital. It was the second time in a week that emergency crews had to respond to the facility for employee complaints of respiratory trouble. Eleven people were hospitalized late last week with difficulty breathing.