Is the general population exposed to ethylene oxide?
Ethylene oxide is present in the environment and is created by various sources, including plants and the heating of cooking oils. The human body also converts ethylene to ethylene oxide. Exposure to ethylene oxide varies across urban, suburban and rural environments.
Ethylene oxide emissions from industrial manufacturing and other applications are strictly regulated under federal and in some cases state and local laws.
How is ethylene oxide regulated for worker safety?
OSHA has set exposure limits for employees working in facilities where ethylene oxide gas is present. In addition, employers must provide appropriate protective clothing and equipment to employees who may be exposed to ethylene oxide. The National Institute of Occupational Safety and Health and the American Conference of Governmental Industrial Hygienists also provide guidance for industrial exposure to ethylene oxide.
Can ethylene oxide cause cancer?
Any potential association between ethylene oxide and cancer is linked only to chronic exposure. There is minimal cancer risk for the general population because most people are not exposed to significant quantities of ethylene oxide.
In fact, one comprehensive lifetime exposure study of workers in ethylene oxide production facilities found no statistically significant excess cancer risk due to ethylene oxide exposure. A similar result was found in Michigan when the state analyzed the population near a facility that used ethylene oxide in Grand Rapids.
Has EPA warned of an elevated risk of cancer due to ethylene oxide exposure levels?
In 2016, the EPA Integrated Risk Information System (IRIS) program released an updated cancer value based on modeling. A number of independent reviews have raised substantive concerns about EPA’s IRIS program generally and its findings with respect to ethylene oxide specifically. For instance, the Texas Commission on Environmental Quality (TCEQ) has said that “EPA’s model over-estimates the cancer potency of ethylene oxide.”
In 2011, the National Academy of Sciences (NAS) also criticized the scientific quality of IRIS assessments—a result of the program’s reliance on overly conservative and default assumptions in its modeling and outdated scientific information. Additionally, two EPA Science Advisory Boards outlined similar and additional issues with the ethylene oxide IRIS assessment.
The ethylene oxide assessment also includes errors in modeling historical exposures to ethylene oxide. These errors combined result in a value that is based on selective science and results in an overly conservative cancer value. In fact, the ethylene oxide cancer value derived from EPA’s modeling is 19,000 times lower than the normal, naturally-created levels of ethylene oxide in the human body.