Skip to main content
U.S. flag

An official website of the United States government

Here’s how you know

Dot gov

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

HTTPS

Secure .gov websites use HTTPS
A lock (LockA locked padlock) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

    • Environmental Topics
    • Air
    • Bed Bugs
    • Chemicals and Toxics
    • Climate Change
    • Emergency Response
    • Environmental Information by Location
    • Environmental Justice
    • Greener Living
    • Health
    • Land, Waste, and Cleanup
    • Lead
    • Mold
    • Pesticides
    • Radon
    • Science Topics
    • Water Topics
    • A-Z Topic Index
    • Laws & Regulations
    • By Business Sector
    • By Topic
    • Compliance
    • Enforcement
    • Guidance
    • Laws and Executive Orders
    • Regulations
    • Report a Violation
    • Environmental Violations
    • Fraud, Waste or Abuse
    • About EPA
    • EPA Administrator
    • Organization Chart
    • Staff Directory
    • Planning, Budget, and Results
    • Jobs and Internships
    • Headquarters Offices
    • Regional Offices
    • Lab and Research Centers
Related Topics:
  • Stationary Sources of Air Pollution
Contact Us

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

Miscellaneous Organic Chemical Manufacturing: National Emission Standards for Hazardous Air Pollutants (NESHAP)
Basic Information
Code of Federal Regulations Citations
  • 40 CFR Part 63 Subpart FFFF
Docket Numbers
  • EPA-HQ-OAR-2003-0121
  • EPA-HQ-OAR-2018-0746

On this page:

  • Rule Summary
  • Rule History
  • Additional Resources
  • Compliance

Rule Summary

The national emission standards for hazardous air pollutants (NESHAP) for the miscellaneous organic chemical (MON) manufacturing industry established emission limits and work practice standards for new and existing miscellaneous organic chemical manufacturing process units, wastewater treatment and conveyance systems, transfer operations, and associated ancillary equipment and implemented section 112(d) of the Clean Air Act (CAA) by requiring all major sources to meet hazardous air pollutants (HAP) emission standards to reflect application of the maximum achievable control technology (MACT).

What's New

January 25, 2022 – EPA responds to several petitions for reconsideration of 2020 MON final rule.  The agency is proposing to reaffirm EPA’s peer-reviewed scientific assessment showing that ethylene oxide is significantly more toxic than previously understood, and to find that it is appropriate to rely upon this assessment in taking regulatory actions to reduce this harmful pollutant.  Read the press release.

The HAP emitted from MON manufacturing facilities include toluene, ethylene oxide, methanol, xylene, hydrogen chloride, and methylene chloride. Exposure to these substances may cause adverse health effects such as irritation of the lung, eye, and mucous membranes, effects on the central nervous system, and cancer.

The final rule will reduce HAP emissions by 16,800 tons per year for existing facilities that manufacture miscellaneous organic chemicals.

See the regulations below for more details.

Rule History

1/25/2022 - Proposed Rule: Reconsideration of the 2020 NESHAP for the MON RTR

8/12/2020 - Final Rule

12/17/2019 - Proposed Amendments

12/17/2019 - Public Hearing and Comment Period Extension

07/14/2006 - Final Rule

12/08/2005 - Proposed Rule

08/30/2005 - Partial Withdrawal of Rule

07/01/2005 - Direct final rule & Proposed Amendments

11/10/2003 - Final Rule

05/01/2002 - Comment Period Extension

04/04/2002 - Proposed Rule

Additional Resources

Reconsideration:

  • Public Hearing Information
  • Fact Sheet: Reconsideration Proposal of the MON Final Risk and Technology Review Amendments (pdf) (1/25/2022)
  • Ficha Informativa: Reconsideración de las Normas Nacionales de Emisiones para Contaminantes Peligrosos del Aire (NESHAP) de 2020 - Industria química orgánica miscelánea (pdf) (Spanish Translation)
  • TỜ SỰ KIỆN: Xem xét lại Tiêu Chuẩn Khí Thải Quốc Gia Năm 2020 Đối Với các Chất Gây Ô Nhiễm Không Khí Nguy Hiểm (NESHAP): Sản Xuất Hóa Chất Hữu Cơ Linh Tinh (pdf) (Vietnamese translation)

Final Amendments:

  • Fact Sheet: Final Risk and Technology Review Amendments

Proposed Amendments:

  • Fact Sheet: Proposed Risk and Technology Review Amendments
  • Webinar slides

Older Fact sheets

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

Compliance

Inspection Tool for the Miscellaneous Organic Chemical Manufacturing NESHAP (240 pp, 2.35 MB, About PDF)

Miscellaneous Organic Chemical Manufacturing MACT training

Contact Us to ask a question, provide feedback, or report a problem.
Last updated on February 22, 2022
United States Environmental Protection Agency

Discover.

  • Accessibility
  • Budget & Performance
  • Contracting
  • EPA www Web Snapshot
  • Grants
  • No FEAR Act Data
  • Plain Writing
  • Privacy
  • Privacy and Security Notice

Connect.

  • Data.gov
  • Inspector General
  • Jobs
  • Newsroom
  • Open Government
  • Regulations.gov
  • Subscribe
  • USA.gov
  • White House

Ask.

  • Contact EPA
  • EPA Disclaimers
  • Hotlines
  • FOIA Requests
  • Frequent Questions

Follow.