Background
The Clean Air Act requires the Administrator to publish a list of air pollutants and issue air quality criteria. In 2024, the EPA Administrator revised the primary annual standard for fine particulate matter from twelve micrograms per cubic meter to nine micrograms per cubic meter, expressly reconsidering a 2020 decision to maintain the higher standard. Industry petitioners and several states challenged the rule, arguing the EPA exceeded its authority and relied on impermissible considerations.
The court’s reasoning
The court analyzed whether the EPA had the authority to revise the National Ambient Air Quality Standards and whether the decision was arbitrary and capricious. The court concluded that the agency acted within its statutory authority and that the inclusion of environmental justice considerations did not render the decision unlawful. The court also found the EPA’s arguments for vacatur lacked merit.
Because these arguments lack merit, we deny the petitions for review and the motion for vacatur.
What it means going forward
The 2024 rule reducing the fine particulate matter standard to nine micrograms per cubic meter remains in effect.