On June 7, U.S. EPA issued proposed amendments to the National Emission Standards for Hazardous Air Pollutants (NESHAP) for Miscellaneous Coating Manufacturing (MCM) facilities. The proposed amendments would establish inorganic HAP standards for process vessels, following the mandated technology review conducted under the Clean Air Act (CAA), originally promulgated in August 2020.

The current MCM NESHAP does not regulate metal HAP from process vessels.

During the manufacturing process, with the addition of raw materials in powder form to paint mixing vessels, emissions of metal HAP in the form of PM emissions may occur and are typically collected and routed to a PM control device (i.e., baghouse, fabric filters, cartridge filters, or scrubbers). EPA’s proposal addresses the currently unregulated metal HAP emissions from this category and proposes Maximum Achievable Control Technology (MACT) for emission sources of metal HAP.

Specifically, EPA is proposing to revise Table 1 of 40 CFR part 63 subpart HHHHH to include the emission limits that apply to process vessels based on the following findings by EPA:

  • Existing sources demonstrate initial compliance with the particulate matter (PM) emissions limit of 0.014 gr/dscf (grains per dry standard cubic foot); and
  • New sources demonstrate initial compliance with the PM emissions limit of 0.0079 gr/dscf.

As proposed, facilities will be required to comply continuously with the standards during all operations that emit metal HAP; but it does not apply to pigments and other solids that are in paste, slurry, or liquid form. The agency also provided a mechanism for owners and operators to demonstrate that materials containing inorganic HAP metals below certain levels are not subject to the standards, as well as a definition for “material containing metal HAP.” (The agency’s proposed monitoring, recordkeeping, and reporting requirements can be found on pages 6-7 of the Federal Register notice).

EPA is proposing a compliance date of one year from the date of a final rule for existing sources.

EPA will be accepting comments on its proposed amendments through Aug. 8, 2022.

Contact ACA’s Rhett Cash for more information.