La Porte firefighters and a Harris County hazmat team have contained a chemical spill Monday after a pipeline ruptured on the northeast side of La Porte in the petrochemical district about 20 miles east of downtown Houston.

Around 4:30 p.m. Monday, residents of La Porte, Baytown and Shoreacres were warned to shelter in place - meaning they should stay inside, shut off air conditioning and close doors and windows.

La Porte police and the city of Shoreacres signaled shortly after 7 p.m. that the incident was resolved. No injuries were reported.

"We have given the all clear," La Porte Police Sgt. Bennie Boles said in a statement. "Roadways are opened."

"The chemical release has been contained," the city of Shoreacres said in a release from the Harris County emergency management office.

The chemical that leaked just north of the interchange between Texas 225 and Texas 146 was anhydrous hydrogen chloride, "which presents symptoms of eye, throat, and nasal irritation," according to a statement issued by the city of La Porte.

A federal safety guide identifies hydrogen chloride as a corrosive poison gas that "can cause serious or permanent injury." The guide describes the chemical as a "colorless gas with a sharp, pungent odor." The non-flammable substance is part of the manufacturing process for "rubber, pharmaceuticals, chemicals, and in gasoline refining and metals processing."

Residents were ordered to shelter in place on La Porte's northeast side, in the area contained by Farrington Road on the west, North Avenue H on the south and Texas 146 on the east.

As a result, the city of Baytown said the Fred Hartman Bridge was closed over the Houston Ship Channel.

A hazmat team from the Harris County Fire Marshal's Office was on scene by 6:30 p.m., agency spokeswoman Rachel Moreno said. They worked with local firefighters and the pipeline company, as Harris County pollution control officials monitored air quality.

"Our team has cleared the scene and is headed home," Moreno said about 7:30 p.m.

La Porte residents had started posting on the city's Facebook page about 5 p.m. asking why sirens were going off and seeking information. The city did not post about the shelter-in-place order until after 5:30 p.m.

Amy Martin, a La Porte resident, said she received an automated text message, phone call and email from the city with instructions to shelter in place because of a "chemical emergency."

The outdoor sirens began to sound a few minutes later, Martin said. She added that she shut off her air conditioning, as instructed, and had yet to get the all-clear as of 6:20 p.m.

A local TV station reported that the spill came from a Valero pipeline, but a company spokeswoman said the incident did not involve the company's infrastructure.

"It's not our asset," Valero spokeswoman Lillian Riojas told the Chronicle in an email. "Hopefully the city of La Porte can identify the company."

The La Porte Police Department did not identify the owner but said that "the company responsible for the line and the cause of the leak is being investigated and will be determined at a later date."