The Independent Clean Air Scientific Advisory Group (I-CASAG) is a group of nationally recognized air quality and public health experts who provide independent, science-based advice to inform national air pollution policy decisions to protect public health.
The Clean Air Act established the US Environmental Protect Agency’s (EPA) Clean Air Scientific Advisory Committee (CASAC) to ensure a body of independent experts informed the agency in the setting of National Ambient Air Quality Standards (NAAQS) that protect human health. In the five decades since, CASAC has helped ensure the nation has science-based air quality standards that have delivered enormous public health benefits, preventing hundreds of thousands of premature deaths every year nationwide.
In early 2025, just days into the second Trump administration, all of the scientists serving on CASAC were dismissed en masse. After a year-long vacancy, in March 2026, the EPA announced its new selection of CASAC members. While previous CASAC members have been dismissed before, the new committee is unusual in the number of members with ties to polluting industries and limited expertise in air quality health effects research. This calls into question their ability to be truly independent when informing decisions that affect the air we breathe.
I-CASAG has been established to ensure that policymakers and the public continue to benefit from the highest levels of scientific expertise, independent review, and constructive feedback when it comes to clean air. Many I-CASAG volunteers are former members of the chartered CASAC and CASAC review panels. They were appointed for their scientific credentials and vetted for conflicts by EPA and bring decades of combined expertise on everything from ozone and particulate matter to urban air pollution and its health impacts.
While no longer a formal federal advisory body, I-CASAG remains committed to transparency, scientific rigor, and the principle that reliable data is vital to guiding environmental policy and making science-informed decisions that protect the nation’s public health.
Our priorities
- Provide independent, expert review of EPA’s Integrated Science Assessment (ISA) and National Ambient Air Quality Standards (NAAQS) as needed
- Provide oversight of current EPA actions and the process by which the agency and CASAC sets ambient air pollution standards
- Offer evidence-based science recommendations to strengthen air quality standards
- Engage with stakeholders, communities, and researchers to build guiding principles and science capacity for future reviews
Suggestions
We welcome your suggestions for topics I-CASAG should review and comment on, as well as agenda items for meetings.
Background and history
The federal science advisory committee system plays an important role in ensuring independent, unbiased, and up-to-date technical expertise informs government decisions across agencies and issue areas. This science advice is also visible to and informed by the public, thanks to the Federal Advisory Committee Act. When federal science advisory committees are shuttered or their independence is compromised, independent science initiatives ensure that sound science-based advice can continue to inform the public and decision makers. Resources are available for forming such independent advisory committees
For instance, in 2019, after the first Trump Administration replaced CASAC members and dismissed a CASAC panel set to inform particulate matter pollution standards, the fired particulate matter panel experts convened independently, forming the Independent Particulate Matter Review Panel.
The independent panel reviewed the state of the science on particulate matter and health effects, and provided independent recommendations on the national particulate matter standards to the EPA, ensuring that the public and the decision makers had access to independent science advice to protect the public from air pollution.
The Union of Concerned Scientists supports this work in partnership with the Environmental Protection Network (EPN).
Independent Science Committees
Additional resources
- Using the FACA Database
- DOWNLOAD: How-to Guide: Running an Independent Science Advisory Committee
- WATCH: Preserving Federal Science Advice: Opportunities for Independent Science Advisory Committees (May 2025)
- Learn more about independent science efforts currently underway
- Using the Federal Advisory Committee Act (FACA) Database to help set up your independent advisory committee
- Eliminating US science advisory committees will harm the public and open the door to special interests (Bulletin of Atomic Scientists, May 2025)
- Safeguarding Against Distortions of Scientific Research in Federal Policymaking (2021)
Our science advisory committee work
- Scientists’ Role in Defending Democracy, co-authored by UCS President and CEO, Gretchen Goldman (Science, August 2025)
- Eliminating US science advisory committees will harm the public and open the door to special interests (Bulletin of Atomic Scientists, May 2025)
- Learn more about our federal advisory committee work on the UCS blog, The Equation.
- Abandoning Science Advice: One Year in, the Trump Administration Is Sidelining Science Advisory Committees (January 2018)
- Scientific Integrity of Federal Advisory Committees: Recommendations for 2021 and Beyond (2020)
- Safeguarding Against Distortions of Scientific Research in Federal Policymaking (2021)
- The Role of Scientists and Engineers on Advisory Committees (Science Network Workshop Series, 2016)