Ethylene oxide and Terumo BCT


In 2016, the U.S. Environmental Protection Agency looked at new information on a chemical called ethylene oxide and established a more protective health level for ethylene oxide in the air. Breathing in ethylene oxide at certain levels over decades may cause an increased risk of certain types of cancers, and it can cause other health effects.
Based on the more protective level and information in the U.S. Environmental Protection Agency’s 2014 National Air Toxics Assessment, released in August, 2018, Terumo BCT Sterilization Services, Inc., 11308 W. Collins Ave. in Lakewood, was identified for further study. The air toxics assessment identified a possible increased cancer risk around Terumo BCT, but was based on computer models, not actual exposures to ethylene oxide.
Terumo BCT is a company that makes medical devices and has been operating in Lakewood since 2001. Like other companies that do this work, it uses ethylene oxide to sterilize medical devices made of plastics, polymers, metals and glass that cannot withstand the high heat and moisture of steam sterilization. Examples of such devices include catheters, resuscitation bags and anesthesia masks.
Terumo BCT is not violating any current air pollution control requirements and voluntarily installed additional controls at the sterilization facility in early September to reduce the amount of ethylene oxide released into the air. The more protective risk level and the most recent air toxics assessment led to the need for additional study.

Air monitoring and health effects studies

The Colorado Department of Public Health and Environment monitored the air twice in the vicinity of Terumo BCT and also monitored the air at other locations in the west Denver metro area (background samples). We monitored first in August, before Terumo BCT installed additional emissions controls, and then in October, after the additional emissions controls were installed. Ethylene oxide levels were significantly lower after the additional controls were installed.
After the air monitoring was complete, we estimated potential cancer risks in the area surrounding Terumo based on current emissions. We also looked at actual reported cancer rates in the area.

What the health effects study found

We found no evidence that there currently is more cancer in the communities around Terumo BCT than in surrounding areas. However, breathing low levels of ethylene oxide similar to those detected in the neighborhood surrounding Terumo BCT over a lifetime may lead to a small increased risk of cancer.
The Colorado Department of Public Health and Environment’s air testing shows Terumo BCT’s installation of additional controls resulted in a two- to five-fold reduction in the cancer risk to residents in the area, and more generally, a significant reduction in ethylene oxide concentrations around the facility. Terumo is further exploring whether there are other control technologies that might further reduce emissions.
Because certain cancers take a lifetime to develop, it could be decades before data would show whether the increased risk is associated with an actual increased rate of cancer.
The exact chance of cancer to people exposed to ethylene oxide in the air around Terumo BCT cannot be known. Exposure depends on how long a person has lived there, wind and weather patterns, how much time is spent outdoors, an individual’s health, and other factors.
The levels of ethylene oxide in our air testing around Terumo BCT were well below levels expected to cause non-cancer health effects.

Questions and answers:

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.

How can I be exposed to ethylene oxide?

Employees of facilities using ethylene oxide may be exposed to it in the workplace. People who live near a source of ethylene oxide, such as Terumo BCT, may breathe it in from the air. It may also be in the outside air in any area at very low “background” levels.

How can ethylene oxide affect my health?

The 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 female breast cancer. Cancer risk for workers increased with higher exposure concentrations and more years of exposure time.
Studies about workers exposed to ethylene oxide show breathing high levels of it over months or years (chronic/long-term exposure) may cause irritation of the eyes, skin, nose, mouth and throat. It also may affect the nervous system, leading to headache, nausea, vomiting, memory loss and numbness. Breathing it at even higher levels for shorter periods (acute/short-term exposure) may result in similar, but more severe, effects. There also is some evidence that higher exposures to ethylene oxide may increase the risk of miscarriage.

What does it mean to have an elevated cancer risk?

In this case, it means that someone exposed to ethylene oxide over many years (a lifetime of exposure) has a slightly increased risk of developing cancer as compared to someone not exposed to ethylene oxide. There are many other factors that can lead to cancer, including heredity and lifestyle choices.
There is some risk of cancer the EPA considers “acceptable.” Up to 100 additional cases of cancer in a million people is within the EPA’s acceptable range.

How can I reduce my risk for cancer?

Cancer is not a single disease, but a group of more than 100 different diseases that share some characteristics. Cancer is common, it is the second leading cause of death in the United States. We recommend people don’t smoke or use tobacco and don’t drink too much alcohol. Limiting time in the sun, increasing exercise, maintaining a recommended body weight, eating a healthy diet, and getting screened for cancer also will reduce your risks.

What is the National Air Toxics Assessment?

The National Air Toxics Assessment (NATA) is a screening tool intended to help EPA and state, local and tribal air agencies determine if areas, pollutants or types of pollution sources should be examined further to better understand potential risks to public health. NATA results are based on computer modeling.


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.
Community members in the area around Terumo BCT who want more information about exposure to ethylene oxide can call the state health department’s toxicology call line at 303-692-2606 or send an email to cdphe_tox