Hidden in the Air: Understanding the Cancer Risks of Ethylene Oxide (EtO)

What You Don’t Know Could Harm You

Ethylene Oxide—commonly referred to as EtO—is a colorless, odorless gas used to sterilize medical equipment and preserve certain foods. But what’s not on the label is what could be silently harming thousands of Americans every year: EtO is a potent cancer-causing chemical, and new government data show the risks are far worse than previously understood.

According to the U.S. Environmental Protection Agency (EPA), long-term exposure to EtO—especially near commercial sterilization facilities—poses serious cancer risks to workers, nearby residents, and even children attending schools or daycare facilities close by. And while consumers using sterilized medical devices or spices are not considered at risk, many people living near EtO-emitting sites may have no idea they're breathing in a toxin linked to leukemia, lymphoma, and breast cancer.

What Is Ethylene Oxide and Why Should You Care?

EtO is widely used across industries—from sterilizing surgical instruments and spices to manufacturing certain consumer products. While it's highly effective at killing bacteria, EtO doesn't simply disappear after use. In fact, it’s released into the air and can remain in surrounding communities for years.

The EPA classifies EtO as carcinogenic by inhalation, meaning that simply breathing air contaminated with EtO over a long period of time can increase your risk of developing cancer. Unlike accidents involving hazardous chemicals, EtO exposure is often chronic, invisible, and unrecognized—until it’s too late.

The EPA’s Findings: What the Science Says

The EPA recently conducted two major risk assessments—one focused on residents living near commercial sterilization facilities, and another on workers directly or indirectly exposed to EtO. Their findings were alarming:

• For workers directly handling EtO in sterilization settings, the cancer risk is as high as:

  • 1 in 17 for commercial sterilization workers

  • 1 in 25 for healthcare facility workers

  • 1 in 36 for spice sterilization workers(over a 35-year career, assuming daily exposure without protective measures)

• For nearby community members, especially those living close to commercial sterilizers:

  • More than 100 in 1 million residents could develop cancer from lifelong exposure

  • Children in nearby schools or daycare centers face elevated lifetime cancer risks

  • Risk increases the closer someone lives or works to a sterilization facility

• EPA’s models assume 24/7 exposure over decades, meaning people who live, work, and raise children near these facilities may unknowingly face substantial long-term health threats.

And this is not speculation—the EPA’s 2016 Integrated Risk Information System (IRIS) determined EtO to be carcinogenic to humans. Additional reports from the National Cancer Institute and ATSDR support these conclusions.

Who Is Most at Risk from EtO Exposure?

📍 Workers on the Front Lines

People working in commercial sterilization plants or hospitals where EtO is used regularly face the highest occupational exposure to EtO. Without rigorous safety measures, their lifetime cancer risk is elevated—significantly.

🏠 Residents Living Near EtO Facilities

Even if you don’t work with EtO, simply living near a commercial sterilizer for decades can raise your cancer risk. The closer your home, school, or workplace is to a facility, the higher the risk.

👶 Children in Nearby Schools or Daycare Centers

Children are particularly vulnerable to airborne toxic exposures, and several schools and daycares fall within high-risk zones around sterilization facilities. For some children, the cancer risk could exceed one in a million simply from breathing local air throughout childhood.

What You Can Do If You’re Concerned

You don’t have to wait for a cancer diagnosis to take action. If you live, work, or raise children near a sterilization facility, here are proactive steps you can take:

🔎 Know Your Location

Use EPA’s public EtO monitoring and modeling tools or contact your local air quality district to find out if you’re near a known EtO emitter.

📞 Get Medical Guidance

Discuss any concerns with your doctor and request regular screenings. Share the ATSDR’s “Clinician Brief: Ethylene Oxide” with your healthcare provider.

• Email: EtO@cdc.gov

• Pediatric Environmental Health Specialty Units (PEHSU): https://www.pehsu.net

📢 Advocate in Your Community

• Talk to local school boards or city councils if schools or homes are near sterilization facilities.

• Demand stronger EtO emission controls and air monitoring from state regulators.

📚 Learn More from Trusted Sources

• EPA’s EtO Information Hub

• ATSDR: Chemicals, Cancer, and You

• EPA’s Health Effects Notebook for Hazardous Air Pollutants

A Final Word: Environmental Justice Demands Our Attention

Many of the communities affected by EtO emissions are already burdened with other environmental and health disparities. That makes this not just a public health crisis—but an environmental justice issue. The people most at risk are often those least informed and least empowered to act.

It’s time to change that.

If you or someone you know lives near a commercial sterilizer, especially in an area with schools, hospitals, or residential housing nearby, share this post. Talk to your neighbors. Reach out to local media. Let the EPA and your state officials know that invisible poisons in our air are unacceptable.

Together, we can demand safer standards, better enforcement, and cleaner air.