EPA Approves Arizona's Fine Particle Air Rules
Published Date: 12/18/2025
Rule
Summary
The EPA is giving a thumbs-up to Arizona’s plan to keep the air clean by following the 2012 fine particle pollution rules. This means Arizona will update its air quality rules, including adding La Paz County to a special air region, starting January 20, 2026. People and businesses in Arizona should get ready for these changes, which help protect health without adding big costs right now.
Analyzed Economic Effects
3 provisions identified: 3 benefits, 0 costs, 0 mixed.
Emergency Episode Plans Added to SIP
The EPA is incorporating Arizona’s emergency episode rules into the SIP, including AAC R18-2-220, the "Procedures for the Prevention of Emergency Episodes," and Maricopa County Regulation VI Rule 600, effective January 20, 2026. These approved plans meet CAA section 110(a)(2)(G) requirements for emergency episode planning for PM2.5.
EPA Approves Arizona PM2.5 SIP Elements
The EPA is approving many of Arizona’s State Implementation Plan (SIP) elements for the 2012 fine particulate (PM2.5) standard, effective January 20, 2026. The approval covers specific CAA infrastructure requirements including sections 110(a)(2)(A), (B), (C) for minor sources, (D)(ii), (E), (F), (G), (H), (J), (K), (L), and (M).
La Paz County Added to Mohave-Yuma AQCR
The EPA is revising federal regulations to add La Paz County to the Mohave-Yuma Intrastate Air Quality Control Region and to the delimited area at 40 CFR 81.268, effective January 20, 2026. The revised classification table for the Mohave-Yuma AQCR (La Paz, Mohave, Yuma) is finalized in the rule text.
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