Ethylene oxide in Colorado


Update: On March 14, 2024 the U.S. EPA announced a new final rule to reduce harmful ethylene oxide emissions and exposures. This new rule applies to four commercial medical sterilization facilities in Colorado. The federal rule is expected to reduce ethylene oxide emissions at these facilities. Learn more

The four commercial medical sterilization facilities in Colorado subject to EPA’s new ethylene oxide rule include:

  • Terumo BCT Sterilization Service, Inc., Lakewood. 
  • Jorgensen Labs, Inc., Loveland.
  • LivaNova, Arvada.
  • Western, Boulder.

What is ethylene oxide?


Ethylene oxide is a chemical used to sterilize heat-sensitive medical equipment.

Ethylene oxide also is used when making antifreeze, textiles, detergents, and other products, and to disinfect spices and tobacco products.



In March 2024, the U.S. The Environmental Protection Agency finalized new rules to reduce ethylene oxide emissions from commercial sterilization facilities and reduce human health risks. Learn more on the EPA’s ethylene oxide website and news release.

Learn more about Colorado’s ongoing work measuring and regulating toxic air contaminants.

Ethylene oxide medical sterilization facilities in Colorado


All medical sterilization facilities in Colorado must comply with state and federal ethylene oxide emissions regulations. As of March 2024, Colorado has four commercial medical sterilization facilities that use ethylene oxide:

  • Terumo BCT Sterilization Service, Inc., Lakewood. 
  • Jorgensen Labs, Inc., Loveland.
  • LivaNova, Arvada.
  • Western, Boulder.

What is Terumo BCT?

Terumo BCT is a company that sterilizes medical devices in Lakewood, CO. The facility has used ethylene oxide for sterilization for more than 20 years. Like other companies that do this work, it uses ethylene oxide to sterilize medical devices that cannot withstand the high heat and moisture of steam sterilization. Examples of such devices include catheters, resuscitation bags, and anesthesia masks.

CDPHE and EPA have worked to reduce emissions and cancer risk in the communities surrounding Terumo BCT in Lakewood, CO since 2018.

This facility was most recently inspected on March 16, 2021. CDPHE determined that Terumo BCT was in compliance with the emission limits in its permit.

Terumo BCT voluntarily installed additional controls in 2018 to reduce the amount of ethylene oxide released into the air. Terumo BCT also said it plans to install more controls in 2024.

Ethylene oxide and health


Employees of facilities using ethylene oxide may be exposed to it in the workplace. People who live near a source of ethylene oxide, including medical sterilization facilities, may breathe it in from the air. It is very difficult to measure ethylene oxide at low levels.

Cancer risk

Breathing in ethylene oxide at certain levels over many years can increase the risk of some types of cancer.
Most studies about ethylene oxide are about people who work with the chemical and who are exposed to it at much higher levels than are found in the air outside. Studies about workers exposed to ethylene oxide show an increased risk of blood cancers (Hodgkin’s lymphoma, non-Hodgkin’s lymphoma, multiple myeloma, and lymphocytic leukemia) and breast cancer. 

Cancer risk for workers increased with higher levels of exposure concentrations and more years of exposure time.

Non-cancer health impacts

Chronic/long-term exposure

Studies about workers exposed to ethylene oxide show breathing high levels of it over months or years may cause irritation of the eyes, skin, nose, mouth, and throat. The levels of ethylene oxide workers are expected to be exposed to is higher than the levels of ethylene oxide found in communities near sterilization facilities. It also may affect the nervous system, leading to headache, nausea, vomiting, memory loss, and numbness. 

Acute/short-term exposure

Breathing ethylene oxide at even higher levels for shorter periods may result in similar, but more severe impacts to breathing it over months or years (see above). There also is some evidence that higher exposures to ethylene oxide may increase the risk of miscarriage.

Children are more susceptible

Children are expected to be more susceptible to health effects of ethylene oxide. This is because ethylene oxide can damage DNA.

More information about ethylene oxide and health: 

Cancer is not a single disease, but a group of more than 100 different diseases that share some characteristics. Cancer is the second leading cause of death in the United States. Each person has a complex genetic makeup, health history, unique exposure history to chemicals, and other risk factors that interact and can lead to the development of cancer. While people can’t control all the factors in their environment, a healthy and active lifestyle, in addition to regular cancer screenings, can lower overall risk.

More information about cancer prevention and risk:




Based on new information about health risks, the U.S. Environmental Protection Agency established a more protective level for ethylene oxide in the air in 2016. In 2018, EPA identified the area around Terumo BCT as having an increased cancer risk, based on emissions modeling. Terumo BCT installed additional emissions controls, and CDPHE conducted air monitoring and health risk studies. In 2022, EPA conducted an additional analysis to model potential impacts to communities from sterilization facilities. EPA’s assessment also showed an elevated cancer risk.

Air monitoring and health risk studies in 2018

CDPHE conducted a health risk study, which looked at cancer risk based on measurements of ethylene oxide in the community. The study also assessed the number of cancer cases in one census tract surrounding Terumo BCT to find out if they were higher than expected. The department found that levels of ethylene oxide in the community were significantly lower after Terumo installed new emissions controls in 2018. The new controls also resulted in a two to five times lower estimated cancer risk. However, the risk was still above the EPA’s “acceptable” level of more than 100 excess cancers in one million exposed people. The department did not find evidence of more cancer cases in the area it analyzed. The levels of ethylene oxide were well below levels expected to cause non-cancer health impacts.

Expanded analysis of cancer rates in 2023

CDPHE conducted an additional study of cancer rates in 2023 and published a supplement to the 2018 health risk assessment. The study included three census tracts and data from 2000-2019. It found small increases in certain types of cancer that are linked to long-term ethylene oxide exposure. The study, conducted in response to community concerns, does not change the risk estimate, nor does it determine whether ethylene oxide caused or contributed to these cancers. This kind of study only establishes the cancer rate and whether it is above what is expected based on cancer rates across Colorado.

Future actions

All the studies conducted so far tell us we need to do more to lower the health risks from ethylene oxide in Lakewood. Terumo BCT has indicated it plans to to install more controls to further reduce emissions from the facility. CDPHE will monitor the air around the facility to understand how well the new controls work. These new controls are expected to lower emissions and risk in communities around Terumo BCT.

More about EPA’s work on ethylene oxide.



If you or your family are concerned about your health or have symptoms you think are caused by exposure to ethylene oxide, discuss these concerns with your health care provider. Consider sharing this fact sheet for health care providers. More information and resources are available under “Learn More About EtO and Your Health” on EPA’s website.

To submit questions or comments about Terumo BCT or ethylene oxide to the CDPHE, email:

If you have questions about EPA’s federal regulations for ethylene oxide, contact eto@epa.gov.