National Emission Standards for Hazardous Air Pollutants: Chemical Manufacturing Area Sources Technology Review

The Environmental Protection Agency (EPA) is proposing to establish a new area source category to address chemical manufacturing process units (CMPUs) using ethylene oxide (EtO). The EPA is proposing to list EtO in table 1 to the National Emission Standards for Hazardous Air Pollutants (NESHAP) for Chemical Manufacturing Area Sources (referred to as the CMAS NESHAP in this document) and to add EtO- specific requirements to the CMAS NESHAP. The EPA is also proposing to add a fenceline monitoring program for EtO. In addition, the EPA is proposing new requirements for pressure vessels and pressure relief devices (PRDs). This proposal also presents the results of the EPA's technology review of the CMAS NESHAP as required under the Clean Air Act (CAA). As part of this technology review, the EPA is proposing to add new leak detection and repair (LDAR) requirements to the CMAS NESHAP for equipment leaks in organic HAP service and heat exchange systems. The EPA is also proposing performance testing once every 5 years and to add provisions for electronic reporting. We estimate that the proposed amendments to the CMAS NESHAP, excluding the proposed EtO emission standards, would reduce hazardous air pollutant (HAP) emissions from emission sources by approximately 158 tons per year (tpy). Additionally, the proposed EtO emission standards are expected to reduce EtO emissions by approximately 4.6 tpy.