TPC Explosion: History and Impact

The TPC explosion was a chemical plant explosion and long-burning fire that began on November 27, 2019, in Port Neches, Texas. A total of 6,000 gallons of flammable butadiene leaked at the Houston-based Texas Petroleum Chemical (TPC Group), forming a vapor cloud that ignited and exploded, injuring several workers and leading to the evacuation of nearly 60,000 people in the surrounding area.

In the aftermath, the Texas Commission on Environmental Quality (TCEQ) sued the facility, alleging violations of clean air and water laws throughout 2018 and 2019. The United States Department of Labor's Occupational Safety and Health Administration also cited the company for exposing employees to workplace safety and health hazards and fined TPC $514,692. Some residents also filed suits against the company, arguing that their health was harmed from significant amounts of hazardous compounds released from the facility.

Chemical Plant Explosion

The explosion occurred in TPC's south unit at its Port Neches facility, which utilizes 1,3-butadiene, a highly flammable and highly reactive liquid used in the production of synthetic rubbers and resins that has been classified as carcinogenic to humans via inhalation. 1,3-butadiene reacts readily in the presence of oxygen, sometimes forming a butadiene peroxide that can concentrate and eventually initiate a fire or explosion, and also sometimes forming "popcorn" polymers (resinous deposits that resemble popcorn) that can grow exponentially and cause equipment to rupture. The processing unit involved in the explosion had developed popcorn polymers in the past.

In the early hours of November 27, a loss of containment event occurred at the facility and 6,000 gallons of primarily liquid butadiene emptied from a fractionator (distillation tower), vaporizing in less than a minute and forming a cloud. Three workers present in the facility indicated that a pipe ruptured, at which point they evacuated quickly, escaping with minor injuries. The location of the initial release was not visually confirmed because the equipment was so heavily damaged.

Within 2 minutes of the initial chemical release, at 12:56 a.m., the vapor cloud ignited and exploded, creating a wave of pressure that damaged numerous buildings around the site and sent debris flying miles away. Two further explosions occurred, one at 2:40 a.m. and another at 1:48 p.m., when one of the facility's towers was propelled into the air. Flammable process equipment continued to leak after the explosion, allowing fires to burn for over a month after the initial blast.

Shortly after the first explosion, authorities in Jefferson County issued an evacuation order for all homes and businesses located within a half-mile radius of the TPC plant. On Wednesday, December 4, the Port Neches Fire Chief issued a shelter-in-place order for the City of Port Neches “out of an abundance of caution.” Later that evening, at 10:00 p.m., the Jefferson County Judge issued a voluntary evacuation order for the City of Port Neches. The next day, on Thursday, December 5, 2019, the Jefferson County Office of Emergency Management said that the shelter-in-place and voluntary evacuation orders were lifted due to improved conditions. Schools did not reopen until December 3, 2019, because officials needed additional time to clean debris, complete structural inspections, and repair school buildings. After returning to school for two days, the schools were closed again, ultimately reopening on December 9.

This back and forth left some residents scared and confused, unsure of air quality as well as whether or not further explosions could propel more debris off-site. Leaks of butadiene continued for more than a month, and oil and petrochemicals washed from the site during firefighting efforts ended up in canals leading to the Neches River.

According to the U.S. Chemical Safety and Hazard Investigation Board's report, ongoing issues with popcorn polymer formation at the TPC group facility prior to the explosion were a probable cause. The south unit had documented problems with popcorn polymers throughout 2019, and the final fractionator A to B transfer pump (that workers observed rupturing) was out of service at the time of the incident. A piping segment that is open to the process but does not have flow through it is known in the industry as a dead leg, which promotes popcorn polymer formation.

TPC Plant Environmental Violations

TPC group had a long record of Clean Air Act violations at its Port Neches facility prior to the November 2019 explosion, dating back two decades. Since 2000, they had paid about $1.5 million for a total of 27 violations of federal law, including 24 citations from the EPA, mostly for releasing hazardous chemicals like butadiene in levels exceeding those considered safe for human health. The $1.5 million that TPC had paid included around $500,000 paid in OSHA fines following the explosion, meaning that for each one of its 24 violations of environmental law over the course of 20 years prior to the incident, the company was fined an average of around $40,000. TPC group's estimated annual revenues are currently more than $220 million, according to financial analysts. Environmental groups and advocates consider the EPA's record of enforcement in Texas largely toothless, as the fines don't ultimately impact the bottom line of businesses that pollute.

Once the TCP explosion occurred, the fourth chemical plant explosion in Texas during 2019, pressure mounted on public officials to hold companies accountable and institute larger fines, or revoke operational permits to repeat offenders that don't address violations. In February 2020, Texas's attorney general filed suit on behalf of TCEQ after the agency's three appointed commissioners rejected staff-recommended penalties for TPC for eight pollution violations from 2018. The recommended penalties weren’t strong enough for incidents that investigators had found to be preventable. Environmental groups see the lawsuit as a positive development, but remain skeptical as to how harshly TCP will ultimately be treated given the state's record of allowing repeat offenders to continue polluting.

Environmental Impact

In the aftermath of the explosion, air monitoring found 240 butadiene air detections above actionable level and 11 VOC detections above actionable levels. Short-term exposure to butadiene causes irritation of the eyes, nasal passages, throat, and lungs. Epidemiological studies have reported a possible association between butadiene exposure and cardiovascular diseases, and studies of workers in rubber plants have shown an association between butadiene exposure and increased incidence of leukemia. The impact of VOCs varies depending on the toxicity of specific compounds, but they have also caused negative health impacts to humans and animals.

Hundreds of people had to be provided with emergency disaster housing immediately after the explosion, and there were 578 properties with observed damage as well as 306 properties with observed debris, some found to contain high levels of asbestos. According to TCP, the company has settled more than 5,000 claims related to impacted homes and has reimbursed over 18,800 residents for evacuation expenses. An insurance firm estimated the cost of damage associated with the incident to be $500 million.

Another significant environmental impact of the explosion came from water flowing from canals at the site into the nearby Neches River as firefighters worked to extinguish flames. According to an investigation by the Beaumont Enterprise using documents requested from Jefferson County, nearly 10,000 booms and dozens of pumps worked to stop oil and hazardous chemicals from flowing out of the site, ultimately killing more than 2,000 fish despite the crew's efforts. Runoff from the facility kept water levels in the canals high as oil and chemicals washed into the waterways, and once the water receded, a "bathtub ring" of oil was left behind on the shore that had to be flushed and raked to remove oiled vegetation and debris.

Cleanup at the facility has continued through 2021, with a demolition phase recently completed to remove debris, clear streets, and to remove damaged equipment. TCP is now using the site as a terminal to transport hazardous chemicals including butadiene and Crude C4, which is used to extract butadiene, while they evaluate and plan to rebuild.

Explosions at petrochemical facilities in Texas did not stop with TCP. In January 2020, a leaking propylene tank exploded at Watson Grinding and Manufacturing in Houston, killing two people. That explosion led city council officials to strengthen regulations for storing hazardous materials. Regulations haven't changed in Port Neches.