Forum
U.S. Supreme Court
Case Status
Pending
Lower Court Opinion
Questions Presented
1. Whether EPA may revise a NAAQS without the “thorough review” required by section 109(d)(1) simply because it acts “earlier or more frequently” than mandated.
2. Whether EPA must consider costs and attainability when exercising discretion to review and revise a NAAQS “earlier or more frequently” than mandated.
Additional Information
U.S. Chamber Urges Supreme Court Review of EPA’s Air Rule That’s Restricting Critical Infrastructure InvestmentU.S. Chamber: New Air Quality Regulations Will Cause Permitting GridlockCase Updates
U.S. Chamber coalition files petition for certiorari in the Supreme Court on whether EPA may revise a national ambient air quality standard off-cycle and without the “thorough” review required by the Clean Air Act, and whether it must consider costs when doing so
August 28, 2026
The Chamber and several leading business organizations, as well as 25 states, asked the U.S. Supreme Court to review a D.C. Circuit decision that upheld a Biden-era Environmental Protection Agency (EPA) rule tightening the National Ambient Air Quality Standards (NAAQS) for fine particulate matter (PM2.5). The Chamber and its fellow associations are concerned about the rule's sweeping consequences for permitting, infrastructure investment, manufacturing, energy production and economic growth.
The vast majority (over 84 percent) of particulate matter emissions now come from non-point sources such as wildfires, construction and road dust – factors that are extremely difficult for individual regions and states to control. By contrast, only 16 percent come from industrial sources and power plants, with further improvements likely as new plants and emerging technologies come online.
As the petition explains, the D.C. Circuit’s decision presents questions of exceptional importance that necessitate Supreme Court review. First, EPA may not revise national air-quality standards outside the Clean Air Act's normal five-year review cycle without first completing a thorough scientific review, as Congress required. Second, EPA must consider the costs and consequences of exercising its authority before deciding to impose a new standard outside the normal review cycle.
The case stems from EPA's 2024 Biden-era Rule that relied on an abbreviated process to lower the annual standard for fine particulate matter, commonly known as PM2.5. The new standard triggers new federal and state regulatory obligations, makes permitting more onerous, and imposes compliance burdens on communities and businesses across the country.
Elbert Lin, Lucinda Minton Langworthy, Erica N. Peterson, and David M. Parker of Hunton Andrews Kurth LLP served as outside counsel.