Cancer-Causing Benzene Pollution from U.S. Refineries Down Significantly

New Data Show that 2015 EPA Benzene Fenceline Monitoring Rules Are Working to Reduce Risks to Nearby Communities

Washington, D.C. – The number of U.S. oil refineries exceeding EPA’s action level for benzene at the end of 2023 fell by half since 2020, suggesting that a new federal program that requires fenceline monitoring for the cancer-causing pollutant and cleanup actions is working to reduce health risks to nearby communities.

Only 6 of the 115 refineries in the U.S. had average annual benzene levels exceeding EPA’s “action level” at the end of 2023, down from nine at the end of 2022, 11 at the end of 2021, and 12 at the end of 2020, according to a new analysis of EPA data by the Environmental Integrity Project (EIP).

EPA’s “action level” for benzene is a regulatory standard created by the agency in 2015 that requires refineries and some chemical plants to conduct investigations and take cleanup actions if benzene levels monitored at the perimeter of facilities exceed an adjusted annual average of 9 micrograms per cubic meter. The agency allows refineries to adjust the monitored levels by subtracting out benzene from offsite sources that may be drifting across a refinery’s fenceline from highways or other plants nearby.

“Requiring companies to publicly disclose their fenceline monitoring results and to find and fix benzene pollution sources appears to be working,” said Eric Schaeffer, Executive Director of the Environmental Integrity Project. “Although we and others are sometimes critical of EPA, this is an example of a success story of regulations working to helping to protect neighborhoods near refineries from a dangerous pollutant.”

In 2018, oil refining companies started monitoring and reporting benzene concentrations measured at the perimeter of their facilities because of 2015 regulations that EPA imposed following a lawsuit by EIP and Earthjustice on behalf of communities neighboring refineries in Texas and Louisiana.

Benzene is a colorless, sweet-smelling chemical – found in oil, gasoline and other petroleum products – that evaporates quickly and is a known carcinogen.

Despite the general downward trend in monitored benzene at refineries over the last four years, some refineries continue to release dangerous levels, according to EPA data examined by EIP.

Of the six refineries that exceeded EPA’s action level at the end of 2023, four were along the Gulf Coast, with two in Texas and two in Louisiana. One was in Ohio (the Toledo Refinery) and another in Hawaii (the Hawaii Refinery.) Click here for a list and EIP’s new searchable website with EPA data on benzene.

The refinery with the highest average in 2023 was the Pemex (formerly Shell) Deer Park Refinery east of Houston, which had an adjusted benzene annual average in December of 17.3 micrograms per cubic meter, which was almost twice the EPA action level. Monitored benzene levels at this refinery have been rising for the last two and half years and above the “action level” for two years.

The second highest was the Chalmette refinery, southeast of New Orleans, which also has been above the “action level” for two years, with an adjusted benzene annual average of 14.67 micrograms in December.

The Total Refinery, in Port Arthur Texas, has exceeded EPA’s “action level” every reporting period since monitoring began in January 2019 and had an adjusted annual average of 13.5 micrograms per cubic meter of benzene at the end of 2023.

On the other end of the spectrum, refineries showing significant improvement over the last three years and now below the “action level” include:

  • LOUISIANA: The Krotz Springs Refinery, located west of Baton Rouge, had an adjusted annual average of 31 micrograms per cubic meter of benzene at the end of 2020 – more than three times EPA’s action level — but that fell to 6 micrograms by the end of 2023.
  • NEW MEXICO: The HF Sinclair Navajo Refinery, located in Eddy, New Mexico, had an adjusted annual average of 25 micrograms per cubic meter benzene at the end of 2020, but that declined to 2 micrograms by the end of 2023.
  • ALABAMA: The Vertex (formerly Shell) Refinery in Mobile, Alabama, had an adjusted average of more than 20 micrograms per cubic meter of benzene at the end of 2020, but that fell to 6 micrograms by the end of 2023.
  • LOUISIANA: The Shell Norco refinery, located west of New Orleans, had an adjusted annual average of 14.6 micrograms per cubic meter benzene at the end of 2020, but that fell to 5.2 by the end of 2023.
  • KENTUCKY: The Catlettsburg Refinery, located east of Lexington, had an adjusted annual average of 10 micrograms per cubic meter benzene at the end of 2020, but that declined to 2 by the end of 2023.

Juan Flores, Community Air Monitoring Program Manager, Air Alliance Houston, said: “It’s great news that the new federal fenceline benzene monitoring requirements have made a significant impact in reducing the release of this dangerous chemical into our communities. I hope for this initiative to continue to reduce these emissions to the lowest possible levels. At the same time, let’s not forget communities that are still suffering from the effects of high benzene levels, such as Deer Park and Galena Park in the Houston area, as well as others nationwide. We must continue to take further strides and actions to provide support to these communities.”

Refineries with adjusted benzene levels over 9 micrograms per cubic meter, measured at their fencelines and calculated on an annual rolling average every two weeks, are required to conduct root-cause analyses to determine the source of the benzene emissions and then take action to reduce the pollution.

Across all refineries – not just those exceeding EPA’s action level at the end of each calendar year – there has been a 30 percent decrease in the number of refineries exceeding the action level at any point in the year, from 24 in 2020 to 17 in 2023, according to EPA data.

The decrease in refineries over the action level since 2020 does not account for the fact that a handful of refineries have site-specific monitoring plans that allow certain refineries to make downward adjustments to exclude benzene from offsite sources, like nearby industrial facilities, and even onsite sources exempt from regulation, like benzene storage tanks.

However, even when taking these adjustments into account, the decline in monitored benzene concentrations since 2020 appears to be significant, according to EIP’s analysis.

In April, EPA expanded its fenceline monitoring regulations to require fenceline monitoring at 218 chemical plants for up to six pollutants—benzene, 1,3-butadiene, ethylene oxide, vinyl chloride, chloroprene, and ethylene dichloride — starting in June 2026, and the first year of data will be published in June 2027.

“With the success of the benzene monitoring program, hopefully this expansion of fenceline monitoring will mean that even more industrial facilities will feel pressure to curb their emissions of dangerous air pollutants into surrounding communities,” said Schaeffer, former director of civil enforcement at EPA.

For EIP’s new interactive map and website with EPA data on benzene, click here.

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

The Environmental Integrity Project is a nonprofit organization dedicated to protecting public health and our natural resources by holding polluters and government agencies accountable under the law, advocating for tough but fair environmental standards, and empowering communities fighting for clean air and clean water.