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

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, 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

07/14/2006 - Final Rule

12/08/2005 - Proposed Rule

08/30/2005 - Partial Withdrawl of Rule

07/01/2005 - Direct final ruleProposed Amendments

11/10/2003 - Final Rule

05/01/2002 - Comment Period Extension

04/04/2002 - Proposed Rule

Additional Resources

Fact sheets

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

Miscellaneous Organic Chemical Manufacturing RTR HEM input files including source ID crosswalks. Please note the inputs are still undergoing review and are subject to change. (For 508 Compliance questions, please contact

MON HEM Input Files(1 pg, 606 K, 9/6/2018)

MON HEM Source ID Crosswalk(1 pg, 829 K, 9/6/2018)

MON HEM Source ID Crosswalk Additional Information(14 MB, 9/24/2018)


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

Miscellaneous Organic Chemical Manufacturing MACT training