Benzene pollution, a known carcinogen, from U.S. oil refineries has decreased since 2020, suggesting that new EPA regulations that require monitoring for benzene along the fencelines of refineries and cleanup actions for the worst polluters are working to help protect nearby neighborhoods, EPA data show.

In 2019, U.S. oil refining companies started reporting benzene concentrations measured at the perimeter of their facilities to comply with 2015 regulations called the Petroleum Refinery Sector Rule. EPA created the regulations in response to a lawsuit filed by the Environmental Integrity Project and Earthjustice on behalf of community groups in Texas and Louisiana, which sought to force EPA to adopt stricter standards to safeguard neighborhoods surrounding refineries.

Under the program, oil refining companies report fenceline monitoring data to EPA every quarter, and if their benzene levels are above an EPA action level, the refinery must conduct investigations and implement corrective measures to reduce pollution.

Recent data show a marked improvement, with only six out of 109 U.S. refineries exceeding the action level by the end of 2023, compared to 12 refineries that exceeded the action level at the end of 2020. Click here to explore the EPA data in an interactive map and benzene dashboard compiled by the Environmental Integrity Project.

Four of the refineries exceeding the EPA action level (a rolling annual average of 9 micrograms per cubic meter, using an adjusted figure described later) in 2023 were on the Gulf Coast, with two each in Texas and Louisiana. (See below for a list) The other two refineries exceeding the action level at the end of 2023 were in Ohio and Hawaii.

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—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.

"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,” said Juan Flores, community air monitoring program manager at Air Alliance Houston. “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."

The refinery with the second highest benzene levels at the end of 2023 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 6micrograms 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 of2020, 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 of2020, 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 of2023.

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.

Click here for more detailed data and maps on benzene monitored at fencelines.

Lead photo: School buses, homes, and businesses located near a massive oil refinery in Texas City, Texas. Photo by iStockphoto.