Air Monitoring Shows Toxic Benzene Levels Inside Coke Oven Plants Far Above Recommended Occupational Safety Limits

Environmental Groups and Citizens Ask Senators to Support Proposed EPA Rule to Reduce Threats to Workers and Nearby Communities

High Benzene Concentrations at Coke Oven Plants Powerpoint presentation available here.

Washington, D.C. –  Air monitors installed within the boundaries of coke oven plants in Indiana, Pennsylvania, and Alabama recorded benzene levels from nearly two to more than fourteen times the occupational exposure limit recommended by the American Council of Governmental Industrial Hygienists (ACGIH).

The high levels of benzene are “exposing plant workers to unhealthy levels of a potent toxin that may also drift into downwind neighborhoods,” the Environmental Integrity Project and 23 other environmental organizations wrote in a letter delivered on Monday to eight U.S. Senators who had earlier complained in a Dec. 6 letter about the high cost of an EPA proposal to minimize emissions of benzene and other toxins from coke ovens.  The letter adds, “We hope you agree that workers inside these plants and those who live nearby deserve the protection that (EPA’s) common-sense approach would provide.”

Benzene is a well-known carcinogen that is toxic at very low concentrations. To help identify sources that leak benzene into the atmosphere, EPA required coke oven facilities in late 2022 to monitor concentrations of this pollutant at locations inside their plants. The ACGIH recommends limiting occupational exposures to no more than 60 micrograms per cubic meter based on an 8-hour average.

  • Eight of thirteen 24-hour benzene samples collected by Indiana’s Cleveland Cliffs Burns Harbor plant ranged from 100 to 910 micrograms per cubic meter, or from almost two to more than fourteen times the ACGIH 8-hour recommendation.
  • All seven of the 24-hour benzene samples collected from US Steel’s Clairton Coke Works in Allegheny County, Pennsylvania, blew past the ACGIH recommendation, recording concentrations from 123 to 620 micrograms per cubic meter.
  • Two of thirteen 24-hour samples at ABC Coke in Birmingham, Alabama, exceeded the ACGIH recommendation.

The peak 8-hour benzene levels during these sampling events, which provide only the average concentration over 24 hours, may have been much higher.

On August 16, 2023, EPA proposed amendments to 20-year-old national emission standards for benzene and other hazardous air pollutants that weaken immune and nervous systems, make it harder to breathe, and contribute to lung and heart disease. While the EPA lacks authority to regulate workplace safety, the proposed standard to identify and suppress emission leaks would protect both workers and communities alike.

Coke ovens convert coal into the coke used in the blast furnaces that make steel, but both coke ovens and blast furnaces are notorious pollution sources with aging infrastructure.

“Steel is a critical part of the U.S. economy,” said Eric Schaeffer, the Environmental Integrity Project’s Executive Director.  “But we need to transition to clean, low-carbon processes that are competitive, safer to operate and live near, and which do not add to global warming. In the meantime, we need EPA’s benzene standards to take effect as soon as possible to protect workers and people living downwind.”

Rob Michaels, Senior Attorney at the Environmental Law & Policy Center, said: “This letter highlights data showing that benzene levels inside and just outside coke oven plants are dangerously high. U.S. EPA’s proposed new standards are a common-sense effort to curb the serious cancer and other risks caused by this toxin.”

Alexander Bomstein, the Executive Director of Clean Air Council, a Pennsylvania organization that works closely with frontline communities, said: “The more we learn about the shockingly high benzene levels in coke plants and at the fenceline, the clearer it becomes how urgently steel workers and the neighboring communities need EPA—and our senators—to protect them from this dangerous carcinogen.”

In their December 6 letter to EPA, U.S. Senators Sherrod Brown (D-OH) and J.D. Vance (R-OH), along with Mike Braun (R-IN), Joe Manchin (D-WV), Bob Casey (D-PA), Amy Klobuchar (D-MN), Shelley Moore Capito (R-WV), and Todd Young (R-IN) complained about the high price of the rules for industry.

“We support reducing harmful air pollution,” the senators wrote. “We also support rules that are durable, realistic, and based upon proven technology and reflect a consensus view among stakeholders on how to best improve public health while protecting good paying jobs.”

The environmental groups signing the letter, which is dated on Friday, March 15, but delivered to the Senators on Monday, March 18, were The Environmental Integrity Project, Allegheny County Clean Air Now (ACCAN), Beaver County Marcellus Awareness Community (BCMAC), Breathe Project, Carnegie Mellon University—CREATE Lab, Citizens Action Coalition, Clean Air Council, Clean Water Action, Common Defense, Earthjustice, Environmental Law & Policy Center, Food & Water Watch, GASP, Group Against Smog & Pollution, Industrious Labs, Just Transition Northwest Indiana, Mighty Earth, PennFuture, Physicians for Social Responsibility, Protect Elizabeth Township, Rail Pollution Protection Pittsburgh (RP3), SWPA Grassroots Air Quality Town Halls, Three Rivers Waterkeeper, and Valley Clean Air Now (VCAN).

For a copy of the letter, click here.

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.

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

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