Houston-area Chemical Leak Claims 2 Lives, Dozens Injured

Deer Park, TX — At least two people are dead, and nearly three dozen others suffered injuries after a chemical leak at an oil refinery Thursday. The incident prompted a shelter-in-place order for Deer Park and Pasadena, officials said.

The leak occurred at a PEMEX facility in Deer Park, about 18 miles east of Houston. The refinery processes crude oil to produce gasoline and other fuels. Around 4:20 p.m., the facility leaked hydrogen sulfide, a colorless gas with a strong odor. Local law enforcement was notified around 5:30 p.m., and local nonprofit Channel Industries Mutual Aid (CIMA) responded, according to a press release by the Deer Park Office of Emergency Management. The shelter-in-place order was issued at 7 p.m. and lifted at 9:30 p.m.

What Caused the Deer Park Chemical Release?

Pemex Deer Park reported "a gas release at one of its operating units" at 4:40 p.m., according to ABC News. The cause of the leak remains under investigation, and the extent of the injuries is not yet known.

USA TODAY has reached out to Pemex and Deer Park Mayor Jerry Mouton for comment.

What is Hydrogen Sulfide?

Hydrogen sulfide is a highly toxic and flammable gas with a foul odor resembling rotten eggs, according to the Federal Occupational Safety and Health Administration. It is produced naturally by bacterial decomposition and is found in sewage, natural gas, and volcanic gases. The gas is used in oil and gas refining, mining, tanning, and paper processing.

Chemical Leak Remains Under Investigation

The incident is still under investigation by the sheriff's office. Officials lifted the shelter-in-place order at 9:30 p.m. after receiving air monitoring reports from Harris County Pollution Control, the Harris County Fire Marshal's Office Hazardous Materials Response Team, and CTEH, according to the sheriff's office.

"We are aware of the odor but there is no hazard to the community," the City of Deer Park posted on social media. "Thank you for your patience."

Where Was the Deer Park Chemical Leak?

The PEMEX facility with the chemical leak is located at 5900 Highway 225.

— USA TODAY contributed to this report.