LA PORTE, Texas -- A gas cloud from a chemical plant forced officials to issue a shelter-in-place and shut down a freeway Thursday afternoon, KPRC Local 2 reported.

The DuPont plant, located at 12501 Strang Road, sounded its siren shortly before noon. Officials said oleum was released from the unit that produces sulfuric acid.

"We had an upset in that process. As a result, we vented a significant amount of sulfuric acid mist," said Ken Martin, DuPont's safety supervisor.

Oleum came out of a 300-foot stack for about 10 minutes. The unit was shut down and the release was stopped but not until after a large cloud covered the area.

"The cloud itself was a very, very fine sulfuric acid mist. I personally drove through the cloud multiple times in my personal car. The thing I would recommend people do if you thought you were exposed to a significant amount of it or your vehicle, something like that, wash it off this afternoon," Martin said.

Residents south of the plant and along Highway 225 were asked to shelter-in-place until it was lifted at 1 p.m. Residents in the Pasadena subdivision of El Jardin were under a shelter-in-place until 1:30 p.m.

La Porte Independent School District schools were included in the shelter-in-place.

Highway 225 was shut down in both directions between at Highway 146 at Sens Road.

No one was injured.

Oleum causes respiratory problems if inhaled. Symptoms include breathing problems and a burning sensation in the throat. Anyone experiencing symptoms is encouraged to see a doctor.

DuPont is investigating how the release happened.

Shelter-In-Place Order

When a shelter-in-place is issued, residents should:

Go inside.
Shut all doors and windows.
Turn off air conditioners and heaters to prevent outside air from getting inside.
Stay off the phone.
Do not use fireplaces. Put out fires and close all dampers.
Move to a room with the fewest windows and doors. Tape around doors, windows, exhaust fans and vents using plastic sheeting or garbage bags, if directed.
Turn on the radio or television to listen for further instructions.

Families are advised to have the following items in a shelter-in-place kit:

Two rolls of duct tape
Cloth and paper towels
Plastic sheets or trash bags
Flashlight and extra batteries
Battery-powered radio
Two gallons of water
Nonperishable foods

If your eyes, nose or throat become irritated, protect your breathing by covering your mouth with a damp cloth, take frequent, shallow breaths and stay calm.

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