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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
Federal Register Citations
  • 89 FR 23840
  • 88 FR 25574
  • 87 FR 77985
  • 87 FR 6466
  • 85 FR 49084
  • 84 FR 69182
  • 84 FR 68870
  • 73 FR 45673
  • 71 FR 40316
  • 70 FR 73098
  • 70 FR 51269
  • 70 FR 38554
  • 68 FR 63852
  • 67 FR 21612
  • 677 FR 16154
Code of Federal Regulations Citations
  • 40 CFR Part 63 Subpart FFFF
Docket Numbers
  • EPA-HQ-OAR-2022-0787
  • EPA-HQ-OAR-2018-0746
  • EPA-HQ-OAR-2003-0121

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).

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.

See the regulations below for more details.

Rule History

04/04/2024 - Petroleum Refinery and Chemical Sector Final Amendments

04/27/2023 - Petroleum Refinery and Chemical Sector Proposed Amendments

12/21/2022 - Final Rule: Reconsideration of the 2020 NESHAP for Miscellaneous Organic Chemical Manufacturing 

02/04/2022 - Proposed Rule: Reconsideration of the 2020 NESHAP for the MON RTR

08/12/2020 - Miscellaneous Organic Chemical Manufacturing Residual Risk & Technology Review Final Rule

12/17/2019 - Miscellaneous Organic Chemical Manufacturing Residual Risk & Technology Review Proposed Amendments

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

08/06/2008 - Miscellaneous Organic Chemical Manufacturing Proposed Amendments

07/14/2006 - Miscellaneous Organic Chemical Manufacturing Final Rule

12/08/2005 - Miscellaneous Organic Chemical Manufacturing Proposed Rule

08/30/2005 - Miscellaneous Organic Chemical Manufacturing Partial Withdrawal of Rule

07/01/2005 - Miscellaneous Organic Chemical Manufacturing Direct final Rule; Amendments

11/10/2003 - Miscellaneous Organic Chemical Manufacturing Final Rule

05/01/2002 - Miscellaneous Organic Chemical Manufacturing Proposed Rule; Comment Period Extension

04/04/2002 - Miscellaneous Organic Chemical Manufacturing Proposed Rule

Additional Resources

Reconsideration:

  • Fact Sheet: Reconsideration of the 2022 MON Residual Risk & Technology Review (pdf) (116.39 KB)
  • Public Hearing Information for the Reconsideration
  • Fact Sheet: Reconsideration Proposal of the MON Final Risk and Technology Review Amendments (pdf) (183.7 KB, 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) (186.41 KB, 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) (234.71 KB, Vietnamese translation)

Final Amendments:

  • Fact Sheet: Final Petroleum Refinery and Chemical Sector Amendments (03/15/2024)
  • Fact Sheet: Final Risk and Technology Review Amendments

Proposed Amendments:

  • Fact Sheet - Petroleum Refinery and Chemical Sector Proposed Amendments (pdf) (156.07 KB)
  • 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 (pdf) (2.35 MB)

Miscellaneous Organic Chemical Manufacturing MACT training

Stationary Sources of Air Pollution

  • Regulations
    • Industry Sector Groups
    • National Emission Standards for Hazardous Air Pollutants (NESHAP)
      • Area Source Standards
      • Risk and Technology Review Status
    • New Source Performance Standards
    • Good Neighbor Plan for the 2015 Ozone National Ambient Air Quality Standards
  • Small Business Assistance Program
Contact Us About Stationary Sources of Air Pollution
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Last updated on March 21, 2025
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