By Treven Pyles on November 13th, 2025 in Ethylene Oxide
EtO is used to sterilize medical devices, sanitize food, and fumigate chemical manufacturing facilities. While the EPA finalized tighter emission regulations in 2024, many years of higher emissions that occurred before these controls remain a significant source of cancer risk for workers and community members who were exposed.
For people diagnosed with EtO-related cancers, grasping why historical emissions continue to hold legal and medical relevance is essential.
The Environmental Protection Agency has classified EtO as a human carcinogen because of evidence that exposure damages DNA. It has been shown that exposure to EtO, even at levels initially considered safe, may lead to lymphohematopoietic cancers such as leukemia, non-Hodgkin lymphoma, multiple myeloma, and breast cancer.
Many facilities, which operated under less stringent emissions controls before 2024, may have exposed surrounding communities and workers to higher levels of emissions for longer periods of time. It has been acknowledged by the EPA that it is years too late to reduce EtO emissions, recognising that for a prolonged period of time, communities are at higher risk for cancer. More recent studies suggest that in some regions, actual exposure levels were higher than previously estimated by environmental monitoring.
According to an EPA study published in 2016, EtO is potentially carcinogenic based on epidemiological, animal, and mechanistic evidence, including genotoxic and mutagenic properties. It has been found that emissions near sterilization and manufacturing facilities often exceed previously acceptable levels, sometimes by orders of magnitude, which drastically increases cancer risk over the course of a lifetime.
Since there is a latency period between exposure and diagnosis, exposures from decades ago are still relevant today. It may take up to 20 years after initial exposure for cancers linked to EtO to develop. This means individuals exposed to higher EtO emissions before 2024 may develop cancer well into the future, even though emission controls have now been tightened.
The National Cancer Institute (NCI) specifically names lymphoma and leukemia among the cancers most frequently associated with EtO exposure, with breast and stomach cancers also linked to the chemical. History emissions from facilities that operated without protective standards for decades can expose communities and workers to EtO via inhalation or ingestion.
Individuals exposed to EtO before 2024 may have strong grounds for legal claims against companies that operated under outdated or lax emission controls. EtO exposure near sterilization plants and chemical facilities has been linked to illnesses such as breast cancer, leukemia, and lymphoma in lawsuits filed by plaintiffs.
Causation can only be established through evidence of past emissions, operational practices, duration of exposure, and proximity to facilities:
Regulators have only recently tightened controls, so historical emission gaps may support claims that companies failed to adequately mitigate risks. It is not uncommon in legal cases to refer to minimum residency requirements or exposure durations, such as living near an emitter for several years or the latency period following the diagnosis of cancer.
In spite of the EPA's recent mandate for emissions reductions starting in 2024 and stricter limits over the next decade, past exposures remain relevant for determining legal liability. Regulatory bodies and courts are recognizing epidemiological and environmental evidence that ties pre-2024 emissions to cancer risk, which may influence settlements and claim outcomes.
Engagement efforts in the community have identified hotspots of elevated cancer risk associated with legacy emissions. Due to increased regulatory scrutiny and corporate accountability, updated cancer risk assessments are strengthening the legal basis for exposure claims.
You may be eligible for compensation if you developed cancer after working at or living near an EtO-emitting facility. With over 30 years of experience handling toxic exposure cases, the Environmental Litigation Group understands the impact of historical emissions on legal claims. When you have been exposed to EtO in the past and developed cancer, we can help you build a compelling case for compensation. Let us help you by scheduling a free consultation.