Contra Costa County health officials are investigating a Friday morning incident at the Dow Chemical plant in Pittsburg that sent thousands of pounds of chemicals into the air.
According to officials with the county Department of Health Services, a tank being used to mix two chemicals overheated around 3 a.m., activating a pressure release device. That sent 3,000 pounds of those chemicals, a fungicide and a solvent, into the air.
Officials say most of the released chemicals fell on Dow's waterfront facility, but some of it traveled east of the the plant over an adjacent wetlands preserve.
The county issued a health advisory, warning that people with respiratory sensitivities in the Antioch and Pittsburg areas could experience eye, nose and throat irritation. No shelter in place or evacuation was issued.
The hazardous materials program sent crews to the area to conduct air monitoring and interview workers at the Dow Chemical plant.
The health advisory was lifted at 5:30 a.m., county health officials said, and no one inside or outside the plant was reported injured.
Dow has operated the plant, which employs about 350 people, since 1939.