On Nov. 27, 2019, a petrochemical facility in Port Neches, Texas, exploded into flames, ignited by 6,000 gallons of butadiene, a highly flammable chemical used in plastics production. The blast was felt up to 30 miles away and burned for more than a month.

The subsequent investigation by the U.S. Chemical Safety Board found that the operator of the plant, TPC Group, failed to identify and address an out-of-service pipe segment, called a “dead leg.” In this dead-end section of pipe, butadiene can accumulate and form clumps of a porous plastic substance known as popcorn polymer, which is dangerous because it multiplies rapidly and can spontaneously combust.  

“The incident at TPC was the result of a known safety hazard — popcorn polymer — that was poorly managed and controlled at the facility,” Steve Owens, the chair of the Chemical Safety Board said at the investigation’s release. “The result was a catastrophic incident.”

After the Port Neches disaster, EPA investigated the company’s operations in Houston and determined that TPC’s Houston facility included at least 63 dead legs. Fifty-three of these dead-end pipes are managed by administrative controls, which allow for human error and the potential for a release and explosions resembling the one in Port Neches.  

Nearly 8,000 people live within a mile of the Houston TPC plant, and 129,000 people live within three miles. These communities are 94 percent people of color, mostly Latino. The population around the Houston plant is significantly larger than the number of people living near the Port Neches plant, and so an accident at the Houston plant could be even more disastrous.

On Sep. 12, 2022, EPA announced an agreement with TPC Houston to correct violations of federal requirements for risk management plans, meant to prevent accidents at industrial facilities. The agreement identifies multiple deficiencies at TPC, including visible external corrosion of equipment and failure to adequately track, manage, and mitigate dead legs.

“EPA investigators found similar conditions in TPC’s Houston facility that led to a dangerous, costly explosion in their Port Neches facility in 2019,” said EPA Regional Administrator Dr. Earthea Nance. “If the company will not hold itself accountable for fixing these issues to protect workers and the surrounding community, EPA will use its authority under the Clean Air Act to do so. EPA is committed to working with and supporting other federal agencies like the Department of Justice on matters that concern the public health.”  

Neil Carman, clean air director for the Sierra Club in Texas said he was not surprised that EPA’s consent degree with TPC Houston highlighted similar problems with managing butadiene that can cause pipes to break.

He said the problems have gone back decades at both the TPC plants, and that the Texas Commission on Environmental Quality (TCEQ) and EPA have failed to address the hazardous characteristics of butadiene polymer.  

“Both TPC plants are very old 1,3-butadiene units and use lots of antiquated process units, pipes, pumps, valves, flanges, etc.,” said Carman. “But the fact is that neither the TCEQ or EPA will order TPC to replace 100 percent of the antiquated process equipment because it's expensive and the regulatory agencies have no authority to order TPC how to operate and run their plant.”

On April 21, 2023, the Environmental Integrity Project sent a letter to U.S. EPA Region 6 requesting that EPA publicly confirm that TPC has taken the corrective actions required to ensure the safe operation of the Houston plant.  

The letter states that, “based on the EPA’s findings at the Houston Plant, it appears that TPC may not yet have learned how to avoid problems that led to one of the biggest industrial accidents in recent years.”

The letter notes that already in 2023, 5,472 pounds of butadiene was released at the Houston facility within a half an hour of a January 12 tank failure. According to the CDC, acute exposure to butadiene can cause eye, nose, throat, and skin irritation, nausea, fatigue, central nervous system depression and, in high enough amounts, respiratory failure.

As of publication, EPA Region 6 has not yet responded to the letter, nor have they responded to questions about TPC’s operations from Oil & Gas Watch News.  

In a statement to the news media, TPC said the company has invested millions of dollars in improving equipment and safety programs since the explosion, and implemented a process to reduce butadiene hazards.

“Although TPC does not agree with every aspect of the final report, we look forward to working with the (Chemical Safety Board) to implement the agency’s recommendations,” said Sara Cronin, TPC Group’s vice president of communications.

Neil Carman of the Sierra Club said EIP’s letter generally speaks to the "piecemeal" air enforcement process pursued by EPA and DOJ in adopting the Consent Decree.

“In the end, it reveals that there are also equally serious limitations in the federal and state agencies’ enforcement powers,” he said. “If they went too far, companies would challenge them in court and bad rulings would occur that would more critically hamper the work of EPA and TCEQ.”

Even without equipment failures or human error, the TPC Houston plant is a major source of hazardous air pollutants and health-threatening air pollutants, including the precursors for ground-level ozone. In 2020, the plant released 510 tons of nitrogen oxides, 108 tons of volatile organic compounds, 73 tons of carbon monoxide, 61 tons of microscopic soot particles (PM 2.5), and 15 tons of sulfur dioxide, according to state records.

According to public records posted on the Environmental Integrity Project’s Oil & Gas Watch website, the TPC Group is now planning to expand production of butadiene and other petrochemical products at the Houston Plant. Located in Harris County, about two miles from the city of Pasadena, the plant manufactures chemicals like butadiene, isobutylene, and polyisobutylene (PIB) that are then used to make products like synthetic rubbers, fuel additives, and plastics.

If approved, the expansion project would increase emissions at the plant by an additional 274,494 tons of greenhouse gases per year and 257 tons of health-threatening air pollutants, such as sulfur dioxide and nitrogen dioxide. Despite the company’s history with chemical fires and illegal releases of dangerous air pollution, TCEQ in June 2022 issued final Clean Air Act pre-construction permits for the company’s proposed expansion project.

The 2019 explosion at TPC’s Port Neches facility forced nearby residents to evacuate and shelter in place. Local schools, showered with debris, were forced to cancel. Over $150 million of off-site property was damaged. An incident of a similar scale at TPC’s Houston facility, located in a denser area, could cause substantially more damage, and endanger countless lives.  

Lead photo: This Aug. 29, 2017, file photo shows the TPC petrochemical plant with downtown Houston in the background (AP Photo/David J. Phillip).