Seyfarth Synopsis: Last week, the U.S. Environmental Protection Agency (EPA or Agency) initiated the first phase of a two phased approach to address ethylene oxide (EtO) emissions, announcing final amendments to the Miscellaneous Organic Chemical Manufacturing National Emission Standards for Hazardous Air Pollutants (NESHAP), known as MON.

Ethylene oxide, a flammable, colorless gas used to make other chemicals that are used in manufacturing a range of products, including antifreeze, textiles, plastics, detergents and adhesives, is also used to sterilize equipment and plastic devices that cannot be sterilized by steam, such as medical equipment. The Agency recently updated its controversial risk value for ethylene oxide (criticized by industry as significantly overstating the risks associated with and safe levels of EtO). As a result, EPA determined it had become necessary to develop rulemaking to reduce EtO emissions consistent with the risk values. Last week's MON rule contains the "technology-based" standards for monitoring and controlling EtO via Maximum Achievable Control Technology (MACT) standards.

Among the requirements of the new standards are controls and operational limits for storage tanks, process vents, transfer racks and heat exchange systems. The operational requirements  and work practice standards include leak control requirements and control of emissions from wastewater streams. There are also new monitoring and control requirements for flares used to control EtO emissions.

Despite the imposition of new control, operational limits, and work practice standards, EPA has estimated that compliance with the standards will reduce EtO emissions by only 0.76 tons per year nationwide. That is, the efforts to be borne by industry are estimated to reduce EtO by only de minimis amounts.

The Final Rule was released on May 29, 2020.  EPA has made a Fact Sheet  on the Final Rule available. It should be noted that this rule will largely only affect miscellaneous specialty chemical production; USEPA has not yet developed specific standards for EtO from commercial sterilizers.

Originally published June 8, 2020

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