An official website of the United States government.

We've made some changes to EPA.gov. If the information you are looking for is not here, you may be able to find it on the EPA Web Archive or the January 19, 2017 Web Snapshot.

Hazardous Air Pollutants: Ethylene Oxide

Ethylene Oxide - Updates

Ethylene oxide monitoring data from July through October 2019 show little change over the previous nine months.

June 25, 2020 - As EPA pursues its mission to protect public health and the environment, addressing ethylene oxide remains a major priority for the Agency. EPA is continuing to examine ethylene oxide monitoring data from two longstanding air toxics monitoring networks: the National Air Toxics Trends Stations (NATTS) and the Urban Air Toxics Monitoring Program (UATMP). Monitors in these networks are located to track progress in reducing air toxics across the country; they are not focused on specific industrial sources.

The Agency recently completed quality assurance/quality control checks on data gathered in July through October 2019 from 17 NATTS and UATMP sites, finding that averages were generally consistent with samples from the previous nine months. EPA now has 12 months of ethylene oxide data from most NATTS and UATMP stations, with averages ranging from about 0.2 to about 0.4 micrograms per cubic meter. EPA has been training laboratories to analyze for ethylene oxide in air quality samples from the other sites in the NATTS and UATMP networks, which currently comprise a total of 33 monitoring sites. Detailed monitoring data are available in EPA’s Air Quality System (AQS), which houses outdoor air quality data collected by EPA, state, local, and tribal air pollution control agencies across the country.


EPA proposes Information Collection Request (ICR) for Ethylene Oxide Commercial Sterilization Facilities

June 5, 2020 - proposed an Information Collection Request (ICR) for ethylene oxide commercial sterilization facilities and is requesting public comment on the action. The data collected through the ICR, in combination with the December 2019 questionnaire that was sent to nine ethylene oxide sterilization companies, will enable EPA to have a better understanding of emissions, emissions sources, processes and control technologies in use at ethylene oxide sterilization facilities nationwide. EPA’s analysis of the ICR data will support the agency’s ongoing review of the Ethylene Oxide Commercial Sterilization and Fumigation Operations National Emission Standards for Hazardous Air Pollutants. EPA will accept comment on the proposed ICR for 60 days after publication in the Federal Register. Learn more here.


EPA finalizes amendments for Miscellaneous Organic Chemical Manufacturing: National Emission Standards for Hazardous Air Pollutants (NESHAP)

May 29, 2020 - EPA finalized amendments to the 2003 Miscellaneous Organic Chemical Manufacturing National Emission Standards for Hazardous Air Pollutants (NESHAP), known as MON. EPA evaluated the risks remaining and determined cancer risks from the miscellaneous organic chemical manufacturing source category to be unacceptable. To reduce risks to an acceptable level, EPA is finalizing additional requirements for process vents, storage tanks and equipment (pumps and connectors) in ethylene oxide service. Once these requirements are implemented, EPA has determined that risks will be acceptable and will provide an ample margin of safety to protect public health.

EPA is also finalizing amendments for heat exchange systems and equipment leaks that would further reduce emissions of hazardous air pollutants. In addition, EPA is finalizing amendments for added monitoring and operational requirements for a subset of flares that control ethylene oxide emissions and flares used to control emissions from processes that produce olefins and polyolefins, and is also allowing facilities outside of this subset to opt into these flare requirements in lieu of complying with the current flare standards.

The final MON amendments are expected to reduce emissions of hazardous air pollutants from the source category by 107 tons per year, which includes reductions in ethylene oxide emission of approximately 0.76 tons per year. 

The final rule, along with a fact sheet and additional information, are available at: https://www.epa.gov/stationary-sources-air-pollution/miscellaneous-organic-chemical-manufacturing-national-emission


Ethylene oxide monitoring data from April through June 2019 show little change over the previous six months.

May 29, 2020 - As EPA pursues its mission to protect public health and the environment, addressing ethylene oxide remains a major priority for the Agency. EPA is continuing to examine ethylene oxide monitoring data from two longstanding air toxics monitoring networks: the National Air Toxics Trends Stations (NATTS) and the Urban Air Toxics Monitoring Program (UATMP). The Agency recently completed quality assurance/quality control checks on data gathered in April through June 2019 from 17 NATTS and UATMP sites, finding that levels were generally consistent with samples from the previous six months. EPA now has nine months of data from the NATTS and UATMP stations, with averages ranging from about 0.2 to 0.4 micrograms per cubic, which is unchanged from the previous six-month averages. EPA has been training laboratories to analyze for ethylene oxide in air quality samples from the other sites in the NATTS and UATMP networks, which currently comprise a total of 33 monitoring sites. Detailed monitoring data are available in EPA’s Air Quality System (AQS), which houses outdoor air quality data collected by EPA, state, local, and tribal air pollution control agencies across the country.


Webinar: EPA’s Proposed National Emission Standards for Hazardous Air Pollutants: Miscellaneous Organic Chemical Manufacturing Residual Risk and Technology Review

On January 21, 2020, the U.S. Environmental Protection Agency (EPA) hosted an informational webinar on the Agency’s proposed amendments to the 2003 Miscellaneous Organic Chemical Manufacturing National Emission Standards for Hazardous Air Pollutants (NESHAP), also known as “the MON.” The purpose of the webinar was to walk attendees through the proposed rule.

The webinar was informational only and not a public hearing. EPA held public hearings on the proposed amendments January 14, 2020 in Houston and January 16, 2020 in Washington, D.C. The Agency is accepting written comment on the proposal until February 18, 2020.

The proposed amendments, along with a fact sheet and other information are available at: https://www.epa.gov/stationary-sources-air-pollution/miscellaneous-organic-chemical-manufacturing-national-emission .

A link to the webinar is available at: https://www.epa.gov/stationary-sources-air-pollution/miscellaneous-organic-chemical-manufacturing-national-emission#additional-resources
 


Public hearings and comment extension for proposed Miscellaneous Organic Chemical Manufacturing NESHAP (MON)

January 14&16, 2020 - EPA held two public hearings to provide interested parties the opportunity to present data, views, or arguments concerning the proposed MON action. The first hearing was held on Tuesday, January 14, 2020, in Houston, TX, and the second hearing was held on Thursday, January 16, 2020, in Washington, DC.

The agency also extended the comment period for the proposed MON to February 18, 2020.


EPA issues advance notice of proposed rulemaking for ethylene oxide commercial sterilization operations

December 5, 2019 - Today, EPA issued an advance notice of proposed rulemaking (ANPRM) to solicit information from the public regarding a potential future rulemaking to revise the standards for commercial ethylene oxide sterilization and fumigation facilities. Specifically, the ANPRM solicits information on suggested strategies for ethylene oxide emission reductions. Addressing ethylene oxide emissions from sterilizers is an Agency priority. The ANPRM will not impose any requirements on the regulated community; rather, it offers the public the opportunity to comment. EPA will accept comment on the ANPRM for 60 days after publication in the Federal Register.

EPA is also taking two additional actions in preparation for a potential future rulemaking for these facilities:

  • Soliciting nominations for representatives for small entities potentially subject to a future rulemaking to advise a Small Business Advocacy Review Panel that would focus on the rule development.
  • Issuing a request for information under CAA section 114 to gather information from several commercial sterilization companies on facility characteristics, control devices, work practices and costs for emission reductions.

Learn more about these actions.


Update on EPA's work to understand air concentrations of ethylene oxide

November 6, 2019 - Today, EPA is providing an update on its work to better understand ethylene oxide – in particular, work to characterize air concentrations of this chemical. EPA is posting initial results of air monitoring for ethylene oxide (EtO) at 18 monitors in the National Air Toxics Trends Stations (NATTS) network and the Urban Air Toxics Monitoring Program (UATMP). Sharing information is an important component of the agency’s two-pronged strategy to address emissions of EtO in the US.

Ethylene oxide is one of 187 hazardous air pollutants or “air toxics” that EPA regulates under the Clean Air Act. It has been determined to be carcinogenic to humans. At the same time, it is an important chemical in our society. It is used to make other chemicals that are the building blocks of a range of products, including antifreeze, textiles, plastics, detergents and adhesives. It is also used widely to sterilize equipment and plastic devices that cannot be sterilized by steam, such as medical equipment. Approximately fifty percent of the sterilized medical devices in this country are sterilized with ethylene oxide. Ethylene oxide in the air can come from different types of sources, including industries such as chemical manufacturers and sterilizers. In 2016, EPA updated its risk value for ethylene oxide and is working with state, local and tribal air agencies to address this chemical.

In 2018 and 2019, EPA and state air agencies monitored the air near industrial sources of ethylene oxide in Lakewood, CO, and Grand Rapids, MI, and Willowbrook, IL as part of follow-up to the most recent National Ambient Air Toxics Assessment or NATA, issued in August 2018. That assessment identified a number of census tracts across the country as potentially having elevated cancer risks from exposure to ethylene oxide in the outdoor air.

Each of the three studies was focused on gathering information on emissions of ethylene oxide from a particular industrial source. In addition to finding elevated levels of ethylene oxide at monitoring sites downwind of the industrial sources, each study also found lower, yet measurable, levels of the chemical at locations upwind, where facility emissions would not be expected to reach air quality monitors.

In light of this information, EPA began to examine whether ethylene oxide is present more broadly in the air in the U.S., and if so, at what levels. To begin this work, the Agency analyzed for ethylene oxide in available air quality samples from a subset of existing, longstanding monitors in the NATTS network and the UATMP network. These networks, which are not focused on specific industrial sources, are designed to help track progress in reducing air toxics across the country. They include monitoring locations in both urban and rural areas. EPA analyzed samples from the subset of these monitors that send samples to EPA’s national contract laboratory for analysis. The results confirmed the presence of ethylene oxide, with six-month averages ranging from about 0.2 to about 0.4 micrograms per cubic meter. The results confirmed the presence of ethylene oxide, with six-month averages ranging from about 0.2 to about 0.4 micrograms per cubic meter. For more information regarding this topic, please visit Data Summary and Map of NATTSUATMP sites.

We believe that there is no immediate, short-term risk from the levels of ethylene oxide found in these limited air monitoring data. There is a need to better understand low levels of ethylene oxide over a longer-term period. EPA will continue to collect information from its existing air monitoring networks and share data as it becomes available.

To this end, EPA has added ethylene oxide to the list of air toxics that will be routinely monitored at all 34 sites in the NATTS and UATMP networks. Because ethylene oxide can be difficult to analyze, the Agency will provide training for states that use their own laboratories to assist them as they begin analyzing air quality samples for this pollutant. Data from future monitoring will be available in EPA’s Air Quality System database after quality assurance is complete.


Update on EPA’s work to review the National Emissions Standards for Hazardous Air Pollutants (NESHAP) for Miscellaneous Organic Chemical Manufacturing and the NESHAP for Ethylene Oxide Commercial Sterilizers.

SEPTEMBER 13, 2019 Today, EPA is providing an update on the status of the Agency’s reviews of two National Emissions Standards for Hazardous Air Pollutants (NESHAP). EPA is reviewing the rules as part of its two-pronged approach the Agency is taking to address emissions of ethylene oxide in the U.S.

A draft proposal for the Miscellaneous Organic Chemical Manufacturing NESHAP is at the Office of Management and Budget for interagency review. EPA expects to issue that proposal for public review and comment as soon as interagency review is complete. The Agency is under a court order to take final action on the rule by March 13, 2020.

For the NESHAP for Ethylene Oxide Commercial Sterilizers, EPA has been working over the past year to compile information on control technology options and costs for the more than 100 sterilizers that the rule would potentially cover.  The Agency intends to take two actions in October to help obtain additional information EPA needs to ensure we have a solid data-based record to support our rulemaking. Those actions include:

  • Issuing an Advance Notice of Proposed Rulemaking (ANPR) that will outline the potential approaches that EPA could take in its upcoming rule, along with the technologies available for controlling ethylene oxide emissions. The ANPR includes an opportunity for public comment, along with an opportunity to provide EPA additional data and information to support the future rulemaking.
     
  • Issuing a request for information to several commercial sterilization companies under section 114 of the Clean Air Act. This will require companies to provide information that would support a proposed rulemaking, including data on specific facility characteristics, control devices, work practices, and costs associated with installation and operation of emission reduction measures.

Separately, because nearly one-third of the sterilizers potentially affected by the rule are small businesses, the Agency may need to convene a Small Business Advocacy Review Panel before taking any significant regulatory action. EPA will request nominations to serve as small entity representatives as part of a possible Small Business Advocacy Review Panel soon. If necessary, this process will inform the formal proposed rule.

EPA plans to issue a proposed rule for ethylene oxide commercial sterilizers in the coming months. The proposal will seek public comment, and EPA will hold a public hearing.