At least two workers were killed and 35 employees injured at a PEMEX oil refinery in Deer Park, Texas, on Thursday. Hydrogen sulfide leaked at the plant, resulting in temporary shelter-in-place orders for residents across the county, officials said.
According to a news release from the City of Deer Park, local police responded to an alert of a chemical leak of hydrogen sulfide—a highly toxic, flammable, and colorless gas often described as smelling like rotten eggs—seeping into the air at the plant around 5:23 p.m. on Thursday.
Two were confirmed dead at the scene, and at least 35 others were “triaged,” Harris County Sheriff Ed Gonzalez said at a Thursday night news conference. It is unclear how many were treated on-site or brought to a medical facility.
Gonzalez said preliminary information showed that workers were working on the flange of some kind when there was a gas leak of hydrogen sulfide. He added that authorities have not made entry into the unit because it is “dynamic” and it might take seven to eight hours, or overnight, to complete the assessment.
“Some of this material that’s a little bit elevated, but it’s contained within the complex itself, so for their safety and decontamination ‘decom’ protocols, we want to make sure those things are taken care of, and we still have to arrange for the bodies to be transported,” he said.
PEMEX, a Mexican state-owned oil company, said in a statement in Spanish that it was investigating the incident. Once the leak was detected and local authorities were notified, operations were stopped to reduce the impact.
Deer Park and Pasadena city officials issued a shelter-in-place order, notifying residents to stay indoors, close all windows and doors, and turn off their air conditioners. The order was lifted hours later after air monitoring determined no hazardous chemicals within the community, city officials said.
“We’ve not gotten any air monitoring reports to show that anything has gotten into the community that would be a concern to any constituents in Deer Park,” Deer Park Mayor Jerry Mouton said, noting air monitoring will be ongoing.
Hydrogen sulfide is used or produced in multiple industries, including oil and gas refining, mining, and pulp and paper processing, according to the Occupational Safety and Health Administration.
State Highway 225 was briefly closed near Beltway 8 but has since been reopened, the sheriff said.
The sheriff’s office will lead an investigation into the incident and work with the fire marshal’s office as well as the Deer Park police, Gonzalez said.