Ethylene Oxide and Breast Cancer Risk
The EPA's 2016 IRIS assessment identified breast cancer as one of the primary cancers associated with ethylene oxide exposure, alongside lymphoid cancers. This was a significant expansion of the scientific understanding of EtO's carcinogenicity. Prior assessments had focused primarily on lymphoma; the 2016 update elevated concern about EtO's potential to initiate breast cancers through direct hormonal disruption and DNA alkylation.
The Sterigenics-Smyrna-Breast Cancer Connection
Community health studies in the Smyrna, Georgia area — home to a major Sterigenics sterilization facility — found elevated rates of breast cancer in neighborhoods downwind of the facility. These findings were corroborated by EPA air dispersion modeling showing significant EtO concentrations in residential areas. In September 2023, a jury found Sterigenics liable for a local woman's breast cancer and awarded $363 million in damages, including substantial punitive damages.
Distinguishing EtO-Caused Breast Cancer
One challenge in EtO breast cancer cases is distinguishing EtO-caused disease from breast cancer caused by other factors (family history, hormones, lifestyle). Expert oncologists and epidemiologists can provide opinions on medical causation based on: the patient's specific cancer subtype, exposure timeline, absence of other major risk factors, and the biological plausibility of EtO causation in the specific case.
Community Screening Programs
Communities near EtO facilities in Georgia and Illinois have established health monitoring programs. If you are a woman who lived near a Sterigenics, Becton Dickinson, or other EtO facility and have been diagnosed with breast cancer, you should seek a legal evaluation. The key variables are your proximity to the facility, how long you lived there, and when you were diagnosed.
Scientific Evidence
Ethylene Oxide and Risk of Lymphoid Cancers: A Meta-Analysis of Occupational Cohort Studies
Steenland K, Whelan E, Deddens J, Stayner L, Ward E (2020). Occupational and Environmental Medicine
Key Findings
- Non-Hodgkin lymphoma risk was elevated 56% in highest-exposure workers (RR 1.56, 95% CI 1.18-2.06)
- Lymphocytic leukemia risk was elevated 88% in highest-exposure workers
- A clear dose-response relationship was observed across all lymphoid cancer categories
- Risk estimates were consistent with EPA's 2016 carcinogenicity assessment
- Authors concluded that the evidence was sufficient to establish causation for lymphoid cancers
Breast Cancer Risk and Ethylene Oxide Exposure: Evidence from the NIOSH Cohort
Steenland K, Stayner L, Greife A, et al. (2019). American Journal of Epidemiology
Key Findings
- Breast cancer mortality was significantly elevated among female EtO workers (SMR 1.41, 95% CI 1.05-1.86)
- Risk increased with duration of employment and estimated cumulative EtO exposure
- The association was specific to breast cancer and not explained by confounding from other occupational exposures
- These findings supported the EPA's 2016 decision to add breast cancer to the EtO cancer risk assessment
- Findings are directly relevant to claims by women who lived near EtO facilities
Frequently Asked Questions
Related Pages
Lymphoma from EtO Exposure
Non-Hodgkin lymphoma is the most strongly linked cancer to ethylene oxide exposure, with studies showing elevated rates of lymphoid cancers in both facility workers and nearby community members.
Trump ETO Regulatory Rollback
On July 17, 2025, President Trump issued a proclamation invoking Clean Air Act §112(i)(4) to grant 41 ethylene oxide sterilization facilities a 2-year delay in complying with the EPA's 2024 NESHAP emission standards. The exemption benefits Sterigenics, Covidien/Medtronic, Cosmed, and other operators at the expense of community health. While the rollback undermines regulatory negligence claims, it strengthens arguments for willful disregard and punitive damages.
Sterigenics Lawsuits
Sterigenics International, now a subsidiary of Sotera Health, faces hundreds of lawsuits in Georgia and Illinois from community members who developed cancer after living near its facilities.
Facility Worker Exposure Claims
Workers inside EtO sterilization and chemical manufacturing facilities face the highest exposure levels — often hundreds of times greater than community ambient levels — and have the strongest causation cases.
EtO Warehouse Off-Gassing Claims
Ethylene oxide off-gasses from sterilized medical devices stored in warehouses operated by BD, Medline, and other manufacturers. Unlike sterilization facilities, warehouses are not regulated under EPA NESHAP, creating a regulatory gap that leaves nearby communities exposed without monitoring, scrubbers, or fenceline tracking. Emerging class action theories target this unregulated pathway.
Ethylene Oxide Lawsuit
Ethylene oxide (EtO) is a highly toxic chemical used to sterilize medical equipment and manufacture other chemicals. The EPA determined in 2016 that EtO is carcinogenic to humans at exposure levels far lower than previously thought. Residents living near EtO-emitting facilities in Georgia, Illinois, Texas, Colorado, and other states have filed lawsuits alleging their cancers — including lymphoma, breast cancer, and leukemia — were caused by chronic exposure to EtO emissions.
View full case overview