An explosion and fire at a chemical plant Thursday in southeastern Louisiana spewed three chemicals, including hazardous vinyl chloride, into the air, authorities said.
No one was injured at the Westlake Vinyls plant in the Geismar community, an area that is home to a large number of chemical plants and refineries that dot the Mississippi River from Baton Rouge to New Orleans.
State police spokesman Russell Graham said it wasn't clear how much gas was released, but a small cloud was hovering over the plant. A handful of residents in the area were advised to stay indoors, keep doors and windows closed and turn off air conditioning units for about three hours.
The Louisiana Department of Environmental Quality also said there were releases of hydrochloric acid and chlorine. State police said the lines involved in the releases had been shut down.
One of the plant's towers was leaning at an angle of 10-12 degrees after the explosion. But Graham said even if it collapsed, more gases would not be released.
"The potential is arguably serious but it's very, very stable right now," said Ascension Parish Sheriff Jeff Wiley. There was "beaucoup air monitoring equipment" stationed around the plant, Wiley said.
"Everything is being monitored," he said.
The plant's owner, Houston-based Westlake Chemical Corp., said the blast occurred about 8 a.m. as a vinyl chloride monomer unit was being restarted. State police said the fire was out by 9:20 a.m.
Karen Khonsari, the plant's environmental, health and safety officer, said the monomer unit was used in manufacturing plastic pipe. All employees were accounted for, she said.
The U.S. Department of Health and Human Services has determined that vinyl chloride is a known cancer-causing substance.
A 44-mile stretch of the nearby Mississippi River was closed as a precaution since winds were blowing in the river's direction, said Ascension Parish spokesman Lester Kenyon. Kenyon said the wind was blowing away from about a dozen residences in the area and other plants. The river was reopened about an hour later.
Westlake Chemical said the cause of the explosion was not known. A line of strong thunderstorms passed through the region Thursday morning.
Several major roads were blocked in the area to all but emergency traffic, Wiley said.
Associated Press writer Alan Sayre in New Orleans contributed to this report.