Ethylene Oxide

Ethylene oxide is a versatile and valuable compound that’s used to help make countless everyday products. Ethylene oxide is used to make household cleaners and personal care items, create fabrics, and manufacture raw materials into more useful forms. A small but important use of ethylene oxide is the sterilization of medical equipment. It’s estimated that more than 50 percent of all medical devices are sterilized with ethylene oxide.

» Learn more about the applications of ethylene oxide

At the end of 2023, ethylene oxide was being produced in the U.S. at 17 facilities in 12 locations by 9 companies. In the U.S., ethylene oxide is primarily produced in two states: Texas and Louisiana.

Ethylene oxide is present in the environment and is created by various sources, including plants and cooking oils. The human body also creates 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.

Protecting the health and safety of the public is a top priority for the producers and users of ethylene oxide and our industry. Companies that make and work with ethylene oxide are actively investing in research and advanced product stewardship technologies so that they can continue to help protect the health of our communities. They continuously revise and improve industry’s safety practices and procedures. As a result of these actions, industrial ethylene oxide emissions have already fallen nationwide by over 80% since 2002. Moreover, one comprehensive lifetime exposure study of workers in EO production facilities found no statistically significant excess cancer risk due to EO exposure. A similar result was recently found in Michigan when the state analyzed the population near a facility that used EO in Grand Rapids.

As an intermediate chemical used to make other products, almost all of the EO is reacted with other substances to form new products.

In 2016, the EPA Integrated Risk Information System (IRIS) program released an updated cancer value based on modeling. ACC believes the value is significantly flawed.

For many years, ACC has raised substantive and serious concerns about EPA’s IRIS program and its lack of transparency, failure to incorporate best available science, and resistance to any reform. ACC is not alone in its concerns.

A number of independent reviews also question the IRIS program and its findings. For instance, the Texas Commission on Environmental Quality (TCEQ) has said that, ‘the USEPA unit risk factor (URF) for ethylene oxide is not scientifically justified.’

Additionally, in 2011, the National Academy of Sciences (NAS) criticized IRIS assessments generally for their poor scientific quality (a result of the IRIS program’s unnecessary reliance on overly conservative and default assumptions and outdated scientific information) and made specific recommendations that were not incorporated into the EO assessment. Two EPA Science Advisory Boards also outlined additional key issues with the EO IRIS assessment.

In its failure to incorporate the 2011 NAS recommended improvements, the EO assessment suffers from the same shortcomings as the IRIS program. The EO assessment also includes significant errors in modeling historical exposures to EO. The result is a value that is significantly flawed, based on selective science, and results in an overly conservative cancer value to the point of absurdity.

In fact, the EO cancer value derived from EPA’s modeling is 23,000 times lower than the normal, naturally-created levels of EO in the human body.

TCEQ has set the record straight on the flawed IRIS value by publishing its own independent, peer reviewed analysis that found the risk of ethylene oxide is 4,000 times lower than the IRIS program concluded. More information about the public health risks of EO can be found on TCEQ’s website.

After TCEQ completed this peer review process, EPA granted ACC’s request that it reconsider the use of the IRIS value in their rulemaking governing emissions from EO facilities producing EO.

For workers in facilities where ethylene oxide gas is present, OSHA has set exposure limits. In addition, employers must provide protective clothing and equipment to employees who may be exposed to ethylene oxide. The National Institute of Occupational Safety and Health (NIOSH) and the American Conference of Governmental Industrial Hygienists (ACGIH) also provide guidance for industrial exposure to ethylene oxide.

Sources of EO emissions to the atmosphere are regulated under EPA’s National Emission Standards for Hazardous Air Pollutants (NESHAP) rules. These regulatory standards require, among other things, the installation of control devices to reduce emissions, emissions monitoring, performance testing, site-specific operating parameters, and continuing reporting and recordkeeping requirements to ensure compliance with the NESHAP rules. The most recent EPA National Emissions Inventory (NEI) is a testament to the effectiveness of these standards, reporting a significant continuing downward trend in national EO emissions for the industrial sector (716.49 tons per year in 2002 to 153.16 tons per year in 2014).

At this time, the EPA is undertaking multiple efforts to address EO emissions, review existing regulations and gather additional information as needed. Additionally, similar efforts are underway at the state level. Read more here: https://www.epa.gov/hazardous-air-pollutants-ethylene-oxide

Companies that make and work with ethylene oxide are actively investing in research and cutting-edge product stewardship technologies so that they can continue to help protect the health of our communities. This starts with the regulations set out by EPA and state agencies. But these companies go beyond simply following regulations. They continuously revise and improve industry’s safety practices and procedures. They are making progress in three ways:

First, these companies have invested millions of dollars in the research and development of rigorous product stewardship guidelines. Second, they use commercially proven technologies that effectively control emissions, and assist in avoiding accidents before they happen. Third, they work together across the industry, sharing excellent practices for safely producing, shipping, and handling ethylene oxide.

There has already been great progress, but companies that make and work with ethylene oxide are not stopping there. They are constantly using what they’ve learned to improve best practices, striving to minimize emissions every day.

The Ethylene Oxide Panel is a leading source of product stewardship and regulatory information on ethylene oxide. The panel promotes the principles of Responsible Care ^® with respect to the safe handling and use of ethylene oxide.

Responsible Careis the chemical manufacturing industry’s environmental health, safety and security performance initiative. Responsible Care provides a foundation to help ACC Ethylene Oxide Panel member companies to safely operate and protect the health and safety of their employees, the communities in which they operate and the environment as a whole.

Ethylene Oxide Panel member companies implement safety technology and practices at every step of the production process – from plant design, to personnel safety precautions, equipment maintenance and preparation, transportation, and loading and unloading operations.

The Ethylene Oxide Panel supports policies based on the best available science and research on health, safety and environmental issues arising from the production, use, storage, transportation and disposal of ethylene oxide.

Ethylene Oxide Panel member companies:

• Share information to enhance operational and emergency response practices to protect public health and our environment
• Produce product stewardship guidance that documents rigorous guidelines for facility design, production, safe handling, and shipment of ethylene oxide, including guidelines for the protection of workers
• Sponsor product stewardship seminars to support the safe manufacture, handling and transportation of ethylene oxide
• Conduct and/or actively participate in toxicology and environmental research to ensure the best available science is publicly available