The stacks and tanks at Dow Chemical’s plant along the Sabine River south of Orange, Texas, look much like the other refineries and chemical plants lining the bays and bayous of Southeast Texas. However, this facility has the highest levels of carcinogenic benzene air pollution measured at its perimeter among all U.S. petrochemical facilities reporting to the EPA, according to the most recent available data.

Benzene levels at Dow’s Orange plant have recently surged, coinciding with the onset of summer, according to EPA data analyzed by the Environmental Integrity Project (EIP). In 2021, EPA mandated that the plant monitor for benzene along its fenceline after the company violated the Clean Air Act.  

Benzene is a colorless, flammable gas with a sweet odor that is among the most potent cancer-causing byproducts of oil and gas operations.  

The EPA requires monitoring for benzene along the fencelines of all U.S. oil refineries and a smaller subset of chemical plants. While concentrations at many refineries have gone down, benzene levels at the Dow Orange plant remain stubbornly high and even reached concentrations more than three times higher than short-term safety thresholds and 33 times higher than a standard for chronic exposure.
 
Air monitoring reveals that the Dow Orange facility has been violating EPA’s “action level” threshold for benzene for a year (meaning that the company is required to take action to reduce the pollution after studying the cause of the problem). The plant is also currently the worst emitter of benzene tracked on EIP’s fenceline monitoring dashboard.  

The Dow plant saw its average benzene concentrations rise dramatically in May and June. The levels at one fenceline monitor near a collection of petroleum tanks spiked from 7 micrograms per cubic meter in the two-week period ending on May 9, to 99 micrograms per cubic meter in the two-week period ending on June 6.  

This concentration of benzene in June was well above a federal short-term safety threshold of 29 micrograms per cubic meter set by the U.S. Agency for Toxic Substances Disease Registry. And it was 33 times higher than what California health officials have established as a threshold for chronic exposure.   The California Office of Environmental Health Hazard Assessment developed a chronic inhalation reference exposure level for benzene of 3 micrograms per cubic meter. This represents the concentration at or below which adverse non-cancer health effects would not be expected from continuous chronic exposure.

Oil & Gas Watch News emailed questions to the EPA asking why the facility has such high benzene concentrations, what enforcement actions it has taken, and what it plans to do to address benzene pollution at the facility. The EPA did not respond.  

Dow spokeswoman Mary Fournier told Oil & Gas Watch News that the company is “working to address the fenceline monitoring at the Orange facility and evaluating a range of corrective actions in compliance with its regulatory requirements.”  

The EPA is responsible for overseeing the benzene monitoring rule, said Ricky Richter, a spokesman for the Texas Commission on Environmental Quality, the state’s environmental regulatory agency. However, the TCEQ has issued $76,800 in fines for environmental violations at the facility over the past five years, records show. Dow also received six written notices of violation from the TCEQ in 2024 alone.  

Ellen Buchanan, chair of the local Golden Triangle Sierra Club group for Southeast Texas, said the air pollution from Dow’s plant represents the “same old, same old” in an area with more than a century of experience with the petroleum industry and industrial logging. Even though cancer rates in the area are relatively high, many residents make a living in the industry and may be reluctant to speak out.  

“We’re the sacrifice zone,” Buchanan said. “People make good money, they have bass boats, they have whatever. But the people they work for make even better money.”  

According to an October 2023 corrective action plan filed with the EPA, Dow attributed high benzene levels in 2022 to a bad seal on the floating roof of a storage tank and said it removed the tank from service. To address the benzene problem, the company also said it cleaned and repaired a piece of equipment that removes butane from natural gas.  

The EPA requires corrective action plans when a facility’s average benzene levels exceed 9 micrograms per cubic meter as a regulatory threshold for requiring cleanup action. (This cleanup action threshold is different than the health threshold for chronic exposure).  As seen in the chart below, Dow’s Orange Plant has been in violation of the action level threshold since monitoring started in July 2023.

Initially, Dow’s corrective actions seemed to reduce benzene concentrations. In the eight months following this work and May 9, 2024, the average two-week concentrations measured at a monitor near rows of petroleum tanks on the northeast side of the plant (at a monitor called SAB_AMP-05) were between 2.35 and 14.6 micrograms per cubic meter of air, averaging 6.52 micrograms per cubic meter of air. These concentrations are lower than the average prior to when the equipment was replaced or repaired (18.49 micrograms per cubic meter), but still well above the health threshold for chronic exposure.  

Close analysis suggests that Dow is still struggling to control benzene pollution at the plant, especially during the summer.  

Since 2022, benzene levels have peaked in June, July, and August, as shown in the chart below. During the summer months in 2022, at monitor SAB_AMP-05, the average concentration was 35.48 micrograms per cubic meter. In 2023, it was 33.28 micrograms per cubic meter.  

This year, the plant has measured some of the highest concentrations ever recorded at the facility.  SAB_AMP-05’s final concentration recorded in May (for the period ending on May 23) was 72.3 micrograms per cubic meter of air, and its first concentration measured in June was 99.1 micrograms per cubic meter of air (a record for the facility as a whole, seen below).  

So even though Dow asserts that the plant’s managers are “evaluating a range of corrective actions” to deal with the benzene pollution problem, the monitoring shows that the company has not yet stopped this serious health threat.  

Lead photo: Dow Chemical’s plant near the Sabine River in Orange County, Texas. Google Streetview image.