Updated:
At least two people have died and multiple others have been injured following a chemical leak at a Pemex oil refinery in Deer Park, Texas, on Thursday, police said.
Up to 35 people at the refinery were treated for exposure to hydrogen sulfide gas. The leak was reported a 4:20 p.m., Harris County Sheriff Ed Gonzalez told a press conference.
The leak occurred as employees were working on a flange, typically used to connect pumps, Gonzalez said.
The sheriff described the situation as fluid and said the current information was preliminary, noting it may take several hours to conduct a full assessment of the incident; possibly even the whole night.
Law enforcement officials are currently working with Mexico-based Pemex to confirm further details surrounding the incident, he noted.
“This incident occurred on PEMEX property, so ultimately, they’re going to have to be the ones to answer and be held accountable for whatever transpired that,” Gonzalez said. “We’re just trying to focus right now on the response, making sure everyone is safe, and that the broader community is safe.”
Air monitoring equipment is currently at the site, Gonzalez said.
“With that said, as the mayor stated, we don’t believe there’s any threat beyond the complex itself unless there’s some type of unplanned upset that may occur,” the sheriff said.
Temporary shelter-in-place orders were issued for residents living in Deer Park, as well as some residents of neighboring Pasadena, immediately after Thursday’s leak, with the city urging people in those areas to stay inside, close all windows and doors, and turn off their air-conditioners until an all-clear was given.
Those orders have since been lifted after Harris County Pollution Control completed air monitoring in Pasadena city limits, city officials said.
A state highway next to the refinery was also closed for a few hours. The highway has since reopened.
In a statement on Thursday, Pemex said emergency protocols were immediately activated after the chemical leak, and the refinery’s Emergency Response Center and local authorities were also notified.
The company said it shut the 92,000 barrels per day coker and a hydrotreater at the refinery after the release began to mitigate the impact.
“No impact on the community has been reported,” it said. “The corresponding investigations are being carried out to determine the causes of the accident and work is being done to reactivate the facilities.”
Hydrogen sulfide is a colorless, potentially toxic, and flammable gas known for its pungent “rotten egg” smell, according to the U.S. Occupational Safety and Health Administration.
The gas is used by or produced as a byproduct across some industries including oil and gas refining, pulp and paper processing, and mining.
Exposure to high concentrations of hydrogen sulfide can irritate the respiratory tract and lead to symptoms such as nausea, headaches, delirium, tremors, and convulsions.
In more extreme cases, inhalation of high concentrations of hydrogen sulfide can lead to death.
Reuters contributed to this report.
