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  2. Particle Pollution Designations

Particle Pollution Designations for the 2024 Revised Annual PM NAAQS - Where You Live

On this page:

  • Initial Designations for States and Territories
  • Initial Designations for Tribes

Initial Designations for States and Territories

On February 7, 2024, the EPA promulgated a revised primary annual PM2.5 NAAQS, strengthening the standard from 12.0 micrograms per cubic meter (µg/m3) to 9.0 µg/m3; retained the existing 24-hour PM2.5 standard at 35 µg/m3; retained the existing 24-hour PM10 (coarse particle) standard at 150 µg/m3; and retained the current suite of secondary PM standards.  After working closely with the states, and affected Tribes, the EPA will complete the routine Clean Air Act process to identify areas as either “nonattainment”, “unclassifiable/attainment”, or “unclassifiable.” Once designations are effective, they guide actions states, Tribes and the EPA must take to improve or preserve air quality in each area.  The EPA will work with the states and Tribes to share the responsibility of reducing fine particle pollution. 


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Initial Designations for Tribes

Tribes can choose to submit their initial designations recommendations to the EPA for the revised 2024 revised primary annual PM2.5 NAAQS no later than 1 year following promulgation of the revised NAAQS, or by February 7, 2025. Tribal areas will be designated on the same schedule as state designations. If a Tribe does not submit designations recommendations, then the EPA will promulgate the initial designations that it deems appropriate. 

Note: This page will continue to be updated with state and Tribal area recommendations, EPA responses, and additional information as the Agency progresses with the area designations process.

Particle Pollution Designations

  • Learn About Particle Pollution Designations
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Contact Us About Particle Pollution Designations
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Last updated on January 17, 2025
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