For generations, the carcinogen ethylene oxide (EtO) has been a mainstay of industrial operations in the U.S., particularly along the Mississippi River between Baton Rouge and New Orleans, an area lined with extensive chemical manufacturing and sterilization facilities.
Roughly 20% of the nation’s ethylene oxide emissions come from this 85-mile petrochemical corridor in Louisiana. It’s known as Cancer Alley because of the high level of illness found there, even as petrochemical emissions continue to enter the air, water, and soil of communities along the river.
One area carries the nation’s highest risk of cancer from industrial pollution—and a new study found that even those risk levels were significantly underestimated.
Ethylene oxide, a clear and highly combustible gas, is able to eliminate microbes without compromising the integrity of delicate materials. It’s typically used to fumigate and decontaminate medical devices.
More than half of all sterile medical equipment used in U.S. hospitals and sold in the nation’s pharmacies has been treated with ethylene oxide. It is deeply integrated into the nation’s healthcare supply chain. Yet the very process that enables crucial devices to reach patients free of harmful pathogens also creates airborne emissions that pose immense dangers to workers and nearby neighborhoods
The substance also poses serious health risks, as recognized by the Environmental Protection Agency (EPA), yet oversight is piecemeal at best. Louisiana workers often experience daily exposure to ethylene oxide without knowing the true scope of its dangers.
Ethylene oxide exposure continues to jeopardize workers
A growing body of research clearly shows that long-term exposure to ethylene oxide can significantly increase the likelihood of blood cancers—such as leukemia and lymphoma—as well as malignancies affecting the connective tissues, brain, lungs, breast, and reproductive organs. Because of such findings, the EPA classified the substance as a human carcinogen in 2016 and even confirmed that frequent contact can boost the odds of developing cancer up to 60 times.
However, the federal agency updated its science quietly, leaving most workers unaware that the air around them had just been linked to a far greater health threat than previously disclosed. The 2018 National Air Toxics Assessment revealed the realities of this hazard in 17 metropolitan areas across the country that face elevated cancer risks associated with industrial emissions.
Among the communities most severely affected are those surrounding the Sterigenics Facility in Willowbrook, Illinois, where air-quality modeling indicated cancer risk levels up to 6,400 per million people—or 64 times the accepted level. Measured emissions near the Midwest Sterilization Corporation in Laredo, Texas, exceeded the federal benchmark by more than 350-fold, posing a tremendous peril to exposed workers.
Louisiana also encounters a comparable threat, especially now, after a July presidential order granted temporary federal exemptions to at least 12 Louisiana facilities that rely on ethylene oxide, allowing them to operate for two whole years without compliance with the EPA’s pollution standards as updated in 2024.
The 12 facilities include the large plants managed by Shell Chemical LP and BASF Corporation in Ascension Parish, by Union Carbide Corporation in St. Charles Parish, by Denka Performance Elastomers in St. John the Baptist Parish, and by Dow Chemical in the town of Plaquemine, in Iberville Parish, the nation’s top ethylene oxide emitter.
These temporary federal exemptions jeopardize the safety and overall well-being of workers that the 2024 EPA rule intended to protect.
Strengthening protections for workers exposed to ethylene oxide
After decades of documented exposure, it has become clear that stronger safeguards are needed to protect workers and communities in Louisiana—and throughout the country—from ethylene oxide emissions. The EPA rule issued in 2024 represents a step in the right direction by imposing stricter emission limits and requiring regular leak inspections at sterilization facilities. That rule is now temporarily suspended for certain facilities. But even if it were in place, the regulatory framework remains insufficient. The responsibility for that framework is split between federal and state authorities, creating gaps in oversight and the provision of consistent safeguards.
Addressing these gaps requires full enforcement of updated emission standards, the elimination of exemptions, and the establishment of continuous monitoring and transparent reporting.
Thousands of workers have already been exposed to ethylene oxide. Simply setting stricter limits and mandating assessments cannot undo years of unmonitored exposure. And for countless workers, the risk persists.
It’s imperative that those already exposed have access to medical evaluations and long-term health tracking. By combining strict and systemic oversight and accountability with proactive healthcare measures, the country can finally secure meaningful protection for its communities.
Jordan Cade is an attorney at Environmental Litigation Group, P.C., a firm in Birmingham, Alabama, that represents victims of toxic exposure nationwide. His work includes litigation involving ethylene oxide and other hazardous emissions from facilities across the United States, including cases impacting communities in Louisiana.
