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Deadly fine particulate matter pollution, also known as soot, comes from tailpipes, smokestacks and industrial power plants. Breathing soot can cause premature death, heart disease, and lung damage. (Chris Jordan-Bloch / Earthjustice)
Press Release April 14, 2026

Coalition Sues Trump EPA for Failure to Implement Life-Saving National Soot Standard

EPA fails to implement its own strengthened air quality standard and missed deadline for identifying areas with soot pollution levels higher than the new acceptable limit

document April 14, 2026

Motion for Summary Judgment: NAAQS Soot Standard

Seventeen health, community and environmental groups filed a lawsuit against the Environmental Protection Agency for failing to implement the strengthened 2024 National Ambient Air Quality Standard (NAAQS) for soot. The coalition also filed a motion for summary judgment asking the court to put the agency on a court-ordered deadline to carry out its overdue responsibility.

document April 14, 2026

Lawsuit filing for EPA Failing to Implement NAAQS Soot Standard

Seventeen health, community and environmental groups filed a lawsuit in the U.S. District Court for the Northern District of California against the Environmental Protection Agency for failing to implement the strengthened 2024 National Ambient Air Quality Standard (NAAQS) for particulate matter air pollution, commonly known as soot.

Deadly fine particulate matter pollution, also known as soot, comes from tailpipes, smokestacks and industrial power plants. Breathing soot can cause premature death, heart disease, and lung damage. (Chris Jordan-Bloch / Earthjustice)
Press Release February 11, 2026

Trump EPA Misses Legal Deadline to Reduce Deadly Air Pollution

Broad coalition of groups condemns illegal inaction, puts EPA on legal notice

document February 10, 2026

Notice of Intent Letter to Sue for Failure to Designate Areas Under 2024 NAAQS

Nearly 20 health, community, and environmental groups around the country officially put the EPA on notice of their intent to pursue legal action unless the EPA issues the overdue designations required under the 2024 National Ambient Air Quality Standard limit for PM2.5, also known as soot.

document December 19, 2025

FOIA: State Designation Recommendations to EPA under NAAQS Record #5 of 5

State recommendations to EPA under the 2024 NAAQS, obtained via a Freedom of Information Act (FOIA) request from Sierra Club.

document December 19, 2025

FOIA: State Designation Recommendations to EPA under NAAQS Record #4 of 5

State recommendations to EPA under the 2024 NAAQS, obtained via a Freedom of Information Act (FOIA) request from Sierra Club.

document December 19, 2025

FOIA: State Designation Recommendations to EPA under NAAQS Record #3 of 5

State recommendations to EPA under the 2024 NAAQS, obtained via a Freedom of Information Act (FOIA) request from Sierra Club.

document December 19, 2025

FOIA: State Designation Recommendations to EPA under NAAQS Record #2 of 5

State recommendations to EPA under the 2024 NAAQS, obtained via a Freedom of Information Act (FOIA) request from Sierra Club.

document December 19, 2025

FOIA: State Designation Recommendations to EPA under NAAQS Record #1 of 5

State recommendations to EPA under the 2024 NAAQS, obtained via a Freedom of Information Act (FOIA) request from Sierra Club.

document December 18, 2025

EPA Abandoning Its Defense of the Soot Standard: Opposition Letter

106 groups oppose EPA abandoning its defense of national health-protective pollution standards for fine particulate matter, also known as PM2.5 or soot.

A refinery is seen at sunset on June 18, 2025 in Houston, Texas. (Brandon Bell / Getty Images)
From the Experts December 17, 2025

Breathing the Consequences: EPA’s Refusal to Implement Strengthened Soot Standard Endangers Public Health

A February 2026 deadline calls for EPA to address air pollution from soot, but it appears the agency has taken few steps, if any, to do so.

document December 17, 2025

Assessing 2024 PM2.5 Standard Implementation So Far: Who’s on Track to Get Clean Air and Who’s Left Behind

In 2024, the U.S. Environmental Protection Agency (EPA) adopted a rule that would initiate a series of actions to reduce exposure to harmful levels of fine particulate matter. This paper assesses where EPA stands in the process of implementing that rule and shines a light on why it is so important to faithfully implement it, as Congress mandated EPA to do under the Clean Air Act.

document March 29, 2023

NAAQS PM 2.5: Technical Comments

Comments of Appalachian Mountain Club, Chesapeake Bay Foundation, Citizens For Pennsylvania’s Future, Clean Air Council, Clean Air Task Force, Clean Air Now, Earthjustice, Environmental Defense Fund, Group Against Smog & Pollution, National Parks Conservation Association, Natural Resources Defense Council, Sierra Club, Southern Environmental Law Center, Union Of Concerned Scientists on the Reconsideration of the National Ambient Air Quality Standards For Particulate Matter

Supreme Court columns reach up toward a blue sky.
(iofoto / Shutterstock)
Article: Victory May 16, 2014

Courts Demand Clean Air for Americans

Over the last few weeks, the nation’s federal courts—including the Supreme Court—have blessed Americans with four major clean air victories.

Article September 18, 2013

Friday Finds: Pushing Clean Air’s Buttons

Tired of breathing dirty air during your daily commute? Just turn on your car vent’s recirculation button, ‘advises researchers from the University of Southern California.

Press Release May 15, 2013

Clean Air Takes Over Capitol Hill

More than 100 physicians, tribal leaders, labor leaders, clergy, nurses, parents to meet with Congress on carbon pollution, smog, ash, other clean air priorities

Article March 12, 2013

Scope of Science: The Dark Side of Soot

Be green: get rid of black