As part of a discretionary reconsideration of a final 2020 decision regarding the fine particulate (PM2.5) National Ambient Air Quality Standard (NAAQS), EPA has lowered the current standard from 12.0 ug/m3 to 9.0 ug/m3. The final rule was published in the Federal Register on March 6, 2024. In the preamble to the final rule, EPA erroneously claimed that it cannot take into account costs and economic impact in setting the new PM2.5 standard. 

Implementation of the Revised Standard

Facility Permit––Beginning May 6, all applicants for permits to construct a new major source or major modification of an existing source will need to conduct an air quality analysis that considers the revised standard.

Nonattainment Designations––Within two years of issuing the revised standard, EPA must designate nonattainment areas for the revised standard (2026). All nonattainment areas are initially designated as “Moderate Nonattainment.” If the area does not meet attainment with the revised standard within six years of the designation (2032), then the area is reclassified as “Serious Nonattainment,” and must meet additional planning requirements and a new attainment deadline 10 years from the initial nonattainment designation (2036). 

State Implementation Plans––Following the nonattainment designations, states must develop and submit to EPA for approval state implementation plans (SIPs) that identify how areas will attain the revised PM2.5 standard. Facilities located in nonattainment areas could face further restrictions on production, bans on new facilities or expansions of existing facilities, stringent new emission limits for PM2.5, and increased regulatory oversight on facility operations and air permits.

Impact of EPA’s New PM2.5 Standard

For the following reasons, the new PM2.5 standard is unnecessary, misguided, and will impose significant economic hardships on the metalcasting industry and U.S. manufacturing. 

Metalcasters Have Decreased PM2.5 Emissions Significantly—EPA recently reported that PM2.5 levels have decreased by 42% since 2000, driven by the existing regulatory controls for particulate matter emissions from stationary sources like metalcasting operations. 

Nonpoint Sources Are Responsible for Most PM2.5 Emissions—Over 80% of PM2.5 emissions in the U.S. are from uncontrolled nonpoint sources such as wildfires, unpaved roads and bare agricultural soils. Even with the removal of all PM2.5 emissions from stationary sources, the new PM2.5 standards could not be attained in many areas due to PM2.5 emissions from natural-occurring nonpoint sources.

Nonetheless, EPA and states will focus on controlled stationary sources to achieve further reductions of PM2.5 emissions.

Economic Impacts of Revised Standard—With the new PM2.5 standard set at 9 µg/m3, approximately 50% of counties nationwide could be designated as nonattainment areas for PM2.5and subject to stringent regulatory requirements, facing further restrictions on production, bans on new facilities or expansions of existing facilities, stringent new emission limits for PM2.5, and increased regulatory oversight on facility operations and air permits. In a study commissioned by the National Association of Manufacturers, the revised standard could threaten nearly $200 billion of economic activity, and put 1 million jobs at risk. 
Background Levels PM2.5––The revised standard is set at or below background levels of PM2.5 in many areas, leaving facilities with little or no room for compliance with the new standards, preventing metalcasters from expanding existing facilities and building new facilities, even with the most effective emissions control technologies already in place.

Metalcasting Serves Supply Chains Critical to U.S. Economy and National Defense—Metal castings are integral to virtually all U.S. manufacturing activities. In the U.S., castings are used to produce 90% of all manufactured durable goods and nearly all manufacturing machinery. Furthermore, metalcasting is vital for national defense. 
EPA Should Have Considered the Economic Burdens of this Rule
Pursuant to the Clean Air Act, EPA is required to review the PM2.5 NAAQS every five years and must set the standard based only on health considerations. Because this final rule is a reconsideration of the 2020 EPA decision to make no changes to the PM2.5 NAAQS, and is not part of the mandated five-year review, EPA is not required to make any changes to the PM2.5 NAAQS at this time. Furthermore, as a reconsideration of the 2020 rule, EPA can and should take costs and economic impacts into consideration. In the preamble to the final rule, EPA erroneously claimed it could not take costs and economic impacts into account in revising the PM2.5 standard. 

Efforts to Minimize Impacts of Revised Standard

Although the revised PM2.5 NAAQS is a final rule, AFS continues to work with industry partners to modify or overturn the rule. AFS has prepared letters to members of Congress urging them to force EPA to minimize impacts of the revised standard on U.S. manufacturing. 
In addition, AFS is part of an industry coalition supporting efforts in Congress to overturn the rule through new legislation and the Congressional Review Act. Finally, a coalition of industry trade groups and a coalition of 24 states have filed legal challenges to overturn the rule. 

In the meantime, AFS members will need to consider possible changes to meet the requirements of the new standard. The AFS Environmental Committees will continue to work on these activities and keep members informed.