A shelter-in-place order in the Texas city of Katy has been lifted after a toxic gas leak at a 99 Cent Only Stores warehouse.
Hazmat crews worked through the night on Saturday to contain the leak of potentially “explosive” anhydrous ammonia at the warehouse on Colonial Parkway, Harris County officials said.
The shelter-in-place order was lifted on Sunday afternoon for residents in a 1.5 square mile area around the University of Houston-Victoria campus in the north of the city, 26 miles west of downtown Houston.
Several agencies responded to an emergency call from the warehouse at about 8.42pm local time on Saturday, Harris County Emergency Services fire chief George McAteer said during a media briefing on Sunday.
The leak was traced to an overhead refrigeration line where crews had been carrying out maintenance, KHOU reported.
Crews said the line was “inaccessible” as it is about 16 feet above the ground, and tried to contain the leak.
At around 1am the gas was detected outside of the warehouse.
Officials have warned residents to immediately seek medical attention if they experience symptoms such as burning eyes, throat and nose irritations or have difficulty breathing.
According to the Centers for Disease Control and Prevention, anhydrous ammonia is a "colourless, highly irritating gas with a pungent, suffocating odour."
The substance is flammable and is normally stored in pressurised containers, the CDC says.
