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Final Miscellaneous Organic Chemical Manufacturing Risk and Technology Review

For a rule summary and history of the Miscellaneous Organic Chemical Manufacturing National Emission Standards for Hazardous Air Pollutants click here.

On 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. 

A pre-publication version of the rule and summary fact sheet are available below.

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