Ethylene Oxide Emissions

Team Lifespan: January 2022 - October 2023

The team products are currently available for external review through June 14, 2023. If you are willing to review the document, please email ITRC's Project Associate Devin Seckar at to get access to the materials.

EtO_V1.jpgITRC's Ethylene Oxide (EtO) Team will explore background EtO, to better differentiate between point and nonpoint source emissions, and the various methods used to analyze EtO to create comprehensive and consistent resources on where, when, and how to analyze and manage EtO. The EtO team will produce fact sheets and informational videos that will be published on ITRC’s website.


Ethylene oxide (EtO) is a flammable, colorless gas used to make other chemicals for a range of products, including antifreeze, textiles, plastics, detergents, and adhesives (EPA, 2020). It is also used to sterilize medical equipment and spices. EtO in the environment is a result of emissions from the production of industrial chemicals, agricultural processes, medical sterilization, and mobile sources such as tailpipes and tobacco smoke. Currently, there are questions about how background EtO should be defined because of mobile source emissions causing disparate levels of EtO in the environment. There are also various analytical methods available and employed to measure EtO, which yields inconsistency in measurement and management. In 2016, the U.S. EPA updated the risk value for EtO, ultimately changing EtO's descriptor from 'probably carcinogenic to humans' to 'carcinogenic to humans.' Nationally, there are 58 'hot spots' with levels of EtO 100x the threshold that triggers the Clean Air Act (CAA). To better manage and effectively communicate risk to communities living near EtO-generating facilities, it is key to differentiate between point or nonpoint source emissions and to establish a consensus on how to measure and analyze EtO in the environment.

Keisha Long

April Lazzaro

Program Advisor