Ethylene Oxide Emissions Standards for Sterilization Facilities: National Emission Standards for Hazardous Air Pollutants (NESHAP)

On this page:

• Rule Summary
• Rule History
• Additional Resources

Rule Summary

This action promulgates National Emission Standards for Hazardous Air Pollutants (NESHAP) for ethylene oxide commercial sterilization and fumigation operations. These standards implement section 112 of the Clean Air Act and are based on the Administrator's determination that commercial sterilization and fumigation operations emit ethylene oxide, a pollutant identified in the Act list of 189 hazardous air pollutants (HAP). The intent of the standards is to protect public health by requiring existing and new major sources to control emissions to the level achievable by the maximum achievable control technology (MACT) and by requiring existing and new area sources to control emissions using generally available control technology (GACT).

Rule History

04/05/2024 - Final Air Toxics Rule for ETO Sterilization Facilities (89 FR 24090) 

06/01/2023 - Extension of Comment Period (88 FR 35808)

04/11/2023 - Proposed Air Toxics Rule for EtO Sterilization Facilities (88 FR 22790)

05/10/2021 - Proposed Information Collection Request, 2nd Notice (86 FR 24862)

05/05/2020 - Proposed Information Collection Request (85 FR 35931)

12/12/2019 - Advanced Notice of Proposed Rulemaking (84 FR 67889)

04/07/2006 - Final Decision (71 FR 17712)

03/25/2005 - Proposal to Exempt Area Source NESHAP from Federal and State Operating Permits (70 FR 15250)

12/19/2005 - Exemption of Certain Area Sources from Title V Operating Permit Programs (70 FR 75320) 

10/24/2005 - Proposed Decision; Request for Comment: Ethylene Oxide Emissions Standards for Sterilization Facilities (70 FR 61404)

11/02/2001 - Final Rule; Amendments: Ethylene Oxide Emissions Standards for Sterilization Facilities (66 FR 55577)

12/14/1999 - Final Rule; Amendments: Title V Operating Permit Deferrals for Area Sources (64 FR 69637)

08/18/1999 - Proposed Amendments: Title V Operating Permit Deferrals for Area Sources (64 FR 45116)

10/23/1997 - Notice: Submission for OMB Review; Comment Request; NESHAP for Commercial Ethylene Oxide Sterilizers (62 FR 55247)

06/03/1996 - Final Rule: National Emission Standards for Ethylene Oxide Commercial Sterilizers (61 FR 27785)

12/13/1995 - Proposed Rule: National Emission Standards for Ethylene Oxide Commercial Sterilizers (60 FR 64002)

12/06/1994 - Final Rule: National Emission Standards for Ethylene Oxide Commercial Sterilization and Fumigation Operations 

03/07/1994 - Proposed Rule: National Emission Standards for Ethylene Oxide Commercial Sterilization and Fumigation Operations

Additional Resources

Reconsideration:

Letter Reconsidering the Ethylene Oxide Sterilizer NESHAP Final Rule (pdf) (148.52 KB, March 21, 2025)

Final rule:

Small Entity Compliance  Guide (pdf) (532.95 KB)

Fact Sheet: Overview of the Final Air Toxics Rule for EtO Sterilization Facilities (updated) (pdf) (217.16 KB) Fact Sheet

Regulatory Impact Analysis for the Final Air Toxics Standards for EtO Sterilization Facilities (pdf) (748.85 KB)

Presidential Memo regarding Ethylene Oxide Sterilizers

Proposed rule:

Fact Sheet: Proposal to Strengthen Clean Air Act Standards for Ethylene Oxide Commercial Sterilizers (pdf) (200.71 KB, April 11, 2023)

Regulatory Impact Analysis for the Proposed NESHAP for Ethylene Oxide Commercial Sterilization and Fumigation Operations (pdf) (711.55 KB)

Public Hearing Registrants:

• EtO Public Hearing Registrants - May 2, 2023 (pdf) (86.02 KB)
• EtO Public Hearing Registrants - May 3, 2023 (pdf) (89.35 KB)

Clean Air Act Section 114 Request:  EtO Sterilizers Section 114 Instructions and Survey (zip)

• Download the zip file above and unzip to your computer to extract the Excel workbooks and the Instructions document.

• Note:  The Excel workbooks and Instructions document provided on this web page should be used if your company did not receive the December 2019 questionnaire issued by the EPA. The companies that responded to the December 2019 questionnaire should refer to the materials enclosed in the package received directly from the EPA.

Press Release: Advance Notice of Proposed Rulemaking on the National Emission Standards for Hazardous Air Pollutants: Ethylene Oxide Commercial Sterilization and Fumigation Operations (12/05/2019)

Fact Sheet: Advance Notice of Proposed Rulemaking on the National Emission Standards for Hazardous Air Pollutants: Ethylene Oxide Commercial Sterilization and Fumigation Operations (12/05/2019)

Small Entity Representative (SER) Nomination Website

Ethylene Oxide Commercial Sterilization and Fumigation Operations NESHAP: Implementation Document

Older Resources:

• Fact Sheets: Final Air Toxics Rules for Ethylene Oxide Emissions from Commercial Sterilization and Fumigation Operations (11/15/1994 and 11/29/1999)
• Fact Sheets: Proposed Air Toxics Standards for Hospital Sterilizers (10/19/2006 and 12/20/2007)

View the supporting documents in the docket folder to find additional related documents to this rule.

Related Rules

Hospital Ethylene Oxide Sterilizers: National Emission Standards for Hazardous Air Pollutants (NESHAP)

Alternative Control Technology Document: Ethylene Oxide Sterilization/Fumigation Operations