Nearly Half of U.S. Refineries Releasing Benzene at Levels That Could Pose a Long-Term Health Threat

New Data from Air Monitors Show Potentially Unsafe Levels of Benzene at Fencelines of 56 of 118 U.S. Refineries; 12 Over EPA Regulatory “Action Level”

(Click here for the online data map and analysis. For video of the press conference, click here.  For audio, click here.)

Washington, D.C. – Air pollution monitors at the fencelines of U.S. oil refineries found that nearly half of them last year were releasing benzene at levels that could pose a long-term health threat to surrounding communities, according to industry data compiled by the Environmental Integrity Project (EIP).

Benzene, a gaseous compound that evaporates from gasoline and other petroleum products, is known to cause a variety of health problems that include anemia, nervous system damage, suppression of immune systems, and leukemia.

According to a new online data map released today by EIP, 56 of the 118 refineries that reported fenceline air pollution monitoring data to EPA in 2021 had annual average benzene readings over three micrograms per cubic meter. That’s the level that California has determined may reduce blood cell counts, undermine immune systems, and increase vulnerability to disease if people are exposed for several years or more.  Annual average concentrations at 51 of the 118 refineries exceeded this level every year since they began monitoring in 2018 or 2019.

“EPA and the oil refining industry really need to do more to crack down on these benzene emissions, because the fenceline concentrations at too many refineries are high enough to pose a potential threat to neighborhoods that are close by,” said Eric Schaeffer, Executive Director of the Environmental Integrity Project. “Fuel prices and refinery profits are up, and these facilities can spend some of that money to better control benzene emissions.”

The very highest annual averages in 2021 were at the Marathon Galveston Bay refinery in Texas City, southeast of Houston, which registered more than 12 times the health threat level; followed by the Total Refinery in Port Arthur (6 times), and Houston Refining (5 times.)  Click here for a complete list, including refineries that were over the health threat level for the last three or four years.

More than six million people live within three miles of a refinery in the U.S., and these nearby communities have low-income and minority populations at rates nearly twice as high as the general population, according to EPA.

“This new analysis shines a bright light on specific sources of a known carcinogen and provides important insight into why the Houston area is an industrial cancer hot spot,” said Jennifer Hadayia, Executive Director of Air Alliance Houston. “Yet, the regulatory agencies responsible for protecting us from cancer-causing air pollution continue to approve permits for these facilities. Pasadena Refining has an active air permit application right now. It’s time to prioritize the health of our fenceline communities over the benefit of industry.”

“This only validates what we already knew,” said John Beard, Executive Director of the Port Arthur Community Action Network. “In a city that has twice the state and national averages of cancer incidence, and in a region that is well known for having a cancer cluster, this should come as no surprise to anyone. How much air pollution is enough to kill people?  There is really no way of knowing exactly how little or how much will cause cancer or make people sick. Any emissions of benzene are dangerous for life and health.”

A 2020 study published in the Journal of the National Cancer Institute concluded that people living within 10 miles of a Texas oil refinery were “statistically significantly more likely to be diagnosed with lymphoma” than people who lived 20 to 30 miles from a refinery.

“No amount of benzene is safe to breathe,” said Dr. Elena Craft, Senior Director for Climate and Health at the Environmental Defense Fund. “Still, Texans are needlessly exposed to it – on top of dozens of other harmful pollutants and toxics. The Texas Commission on Environmental Quality has to start holding polluters accountable. Relying on them to self-regulate hasn’t been a successful strategy. The agency must coordinate with the EPA to deliver solutions now to remove this cancer-causing chemical from the air.”

EIP’s analysis is based on the annual average of the highest two-week average fenceline benzene monitoring concentrations per monitoring period reported by refineries to EPA. It is worth noting that the actual risk to public health depends on how much and for how long the benzene measured at the refinery fencelines drifts into surrounding neighborhoods. The actual benzene levels in communities closest to refineries is rarely monitored in a continuous way.

Twelve of the refineries last year had benzene readings at their fencelines that were so high they not only exceeded the 3 microgram per cubic meter health threat level set by California, but also exceeded EPA’s regulatory “action level” threshold that is supposed to require corrective action by industry. The action level is set at an annual average of 9 micrograms per cubic meter, after excluding background and offsite concentrations.

Among the 12 refineries over EPA’s action level for benzene in 2021, five were located in Texas (two in Houston, and one each in Texas City, Port Arthur, and Corpus Christi); four were in Louisiana; and one each were in Philadelphia, southern Indiana, and the U.S. Virgin Islands. For a list, click here or see chart at bottom.

The industry air monitoring data is available to the public though EIP’s online data map because of new EPA regulations.  In 2012, the Environmental Integrity Project and Earthjustice filed a lawsuit against EPA on behalf of seven community and environmental groups, including Air Alliance Houston and the Louisiana Bucket Brigade, to force the agency to adopt stricter standards to protect people living closest to oil refineries.

In response, EPA adopted new federal regulations that require petroleum refineries to monitor benzene concentrations along their fencelines and report the results to the EPA every three months. If the monitoring data identify annual average benzene concentrations above the “action level” after excluding background and offsite concentrations, refineries are required to conduct a root-cause analysis to identify and clean up the emission sources causing that problem.

By 2018, refineries across the U.S. started measuring two-week average benzene concentrations at locations around their fencelines using a network of monitors. The Table below identifies the fenceline benzene concentrations for the 12 refineries exceeding the action level in 2021, as well as their benzene levels from 2018 to 2020.

Annual Net Benzene Levels at Fencelines of Refineries that Exceeded EPA’s Action Level (9 micrograms per cubic meter) in 2021

Refinery Annual Average Net Benzene Levels (micrograms per cubic meter)
2018 2019 2020 2021
Marathon Galveston Bay Texas City (TX)** 8.6 12.0 15.1 19.8
Philadelphia Energy Solutions (PA) 18.8 49.5 27.4 18.5
Total Refinery Port Arthur (TX) 27.3 16.7 16.6 17.7
Valero St Charles Norco (LA) 2.6 2.7 3.0 14.1
Shell Norco Manufacturing Complex (LA) 8.3 8.5 14.4 13.9
Chalmette Refining (LA) 14.1 15.0 11.2 11.9
Countrymark Refining and Logistics (IN) 4.5 5.3 5.8 11.5
Pasadena Refining (TX)** 14.5 30.0 7.0 11.0
Phillips 66 Lake Charles Westlake (LA) 5.1 6.2 10.8 10.5
Flint Hills Resources Corpus Christi East Refinery (TX) 14.8 13.7 6.7 10.4
Houston Refining LP (TX)** 1.9 5.4 8.6 9.7
Limetree Bay Terminals Christianstead (VI)* 2.9 3.6 9.4

Source: Industry reports to EPA.  Net benzene concentrations are adjusted to exclude contributions from background and offsite sources. * The Limetree Bay refinery did not start monitoring until 2019.** These refineries have site-specific monitoring plans (SSMPs)

Notes on Data:

To evaluate the risk to public health, EIP used the California Environmental Protection Agency’s chronic Reference Exposure Level of 3 micrograms per cubic meter, which is meant to prevent damage to blood-forming cells that can lead to anemia, reduced immune function, and other health problems. Short-term exposure to higher levels of benzene can cause headaches, dizziness, and irritation to the eyes, skin, and respiratory tract, as well as damage to the immune and blood systems.

In addition to the noncancer health impacts of benzene exposure, benzene is a known carcinogen linked to elevated risk of leukemia. Though there is no “safe” level of benzene exposure, EPA estimates that breathing benzene at an average concentration of three micrograms over a lifetime could result in two additional cancer cases per 100,000 people exposed.

California estimates an even lower concentration of benzene could increase cancer risk, and that lifetime exposure to three micrograms per cubic meter could result in eight excess cancer cases among 100,000. As benzene levels rise, those risks increase proportionately.

In 2015, EPA established an action level of nine micrograms per cubic meter which, when exceeded, requires refineries to conduct a root-cause analysis and take corrective action to reduce benzene emissions. The agency determines compliance with the regulation by calculating a rolling annual average of net benzene concentrations. The net benzene concentration is the difference between the highest and lowest concentrations (representing “background” benzene levels) detected by the refinery’s fenceline network during a two-week monitoring period. If this net annual average exceeds nine micrograms per cubic meter, the owner of the refinery must investigate and take corrective action.

To read more and access EIP’s full online data map, click here.

The Environmental Integrity Project is a 20-year-old, nonprofit organization, based in Washington, D.C. and Austin, Texas, dedicated to enforcing environmental laws and strengthening policy to protect public health and the environment.

Media contact: Tom Pelton, Environmental Integrity Project (443) 510-2574 or