A Texas city ordered residents to take shelter indoors for several hours on Thursday morning for what was the second time in a week as the air quality there worsened after a fire at a petrochemical storage facility.

Officials in the city, Deer Park, which is about 20 miles east of Houston, lifted the latest shelter-in-place order at 11:40 a.m., about seven hours after putting it in place. The order had been prompted by the levels of benzene in the air.

In a statement, emergency services and public health officials said that air quality readings in the area had improved for a sustained period of time, allowing the city to lift the order.

“Air quality readings are improving, and over the last few hours, they have been significantly reduced,” said Robert Hemminger, the city’s emergency services director. “This information, combined with the assurance of Harris County Public Health, allows us to meet our internal criteria necessary to lift our shelter-in-place.”