Texas officials are investigating a chemical spill that prompted a shelter-in-place order

A shelter-in-place order issued Sunday morning for parts of Texas’ most populous county was lifted by early afternoon, local officials said. The order applied to parts of Harris County, which includes Houston and is home to more than 4 million residents, and was issued in response to a chemical gas leak at a 99 Cents Only Store distribution center about 30 miles west of the city.

An investigation into the leak from the warehouse and what caused it is currently underway, the CBS affiliate reported HOWE informed. The facility, located off the freeway in the smaller city of Katy, will remain closed while the investigation is underway, according to the station.

“At this time we believe it is safe to lift the shelter in place and we will continue to work to control the contamination throughout the evening,” said Dr. Erica Brown, director of public health and wellness at Harris County Public Health during a press conference.

The chemical leak began around 9:00 p.m. Saturday night, county officials said earlier. They explained that maintenance crews were performing routine work on the warehouse’s refrigeration system and initially tracked down the leak after it started in the overhead refrigeration line. The line itself is suspended about 16 feet in the air, said Fire Marshal Lori Christensen, which initially made it “inaccessible” to the hazardous materials team sent in as part of the county’s containment plan.

Christensen said that “because of how high [the line] and the fact that it’s an explosive product,” the hazmat team “couldn’t initially go in there and do anything about it.”

Maintenance workers noticed that a chemical, later identified as anhydrous ammonia, began leaking from the building around 1 a.m. Sunday morning, officials said. No injuries have been reported from the spill, but potential threats to air quality and human health have prompted the Harris County Department of Public Health to issue a shelter-in-place order for residents within a two-mile radius of the spill. center

“Our landlord’s certified refrigeration contractor was performing work on the refrigeration system when the release occurred,” the 99 Cents Only Store said in a statement obtained by CBS News.

“The safety of our employees, other people in the building and our community is always our top priority. The building was immediately evacuated as soon as the leak was discovered,” the statement said. “Construction work will not resume until we confirm the cause of the release, the matter is fully resolved, and state and local officials report that the facility is safe for normal operation.”

Ammonia leaks are dangerous because of the chemical’s flammability, Fire Chief George McAteer explained, and because of its potential to cause respiratory symptoms and irritation of the nose and throat when exposed to contaminated air.

Ammonia, one of the most widely produced chemicals in the U.S., is a clear, colorless, odorless compound called anhydrous ammonia in its purest form, the county health department said in an advisory. Twitter. Although low levels of ammonia are found in household products such as detergents, high and potentially dangerous concentrations of the chemical “are used in manufacturing, refrigeration and agriculture (as fertilizer),” according to the CDC.

“If anyone experiences watery eyes, burning eyes, irritation in the nose or throat, difficulty breathing, we ask that you go to the nearest emergency center to get help,” Brown said, discussing the chemical spill on Sunday. “If anyone has any chronic medical conditions or feels they have health risks, we ask that you contact your healthcare provider to determine next steps.”