(WASHINGTON, D.C. – May 22, 2025) Today, the U.S. House voted 216-212 to pass a Congressional Review Act resolution to overturn longstanding Clean Air Act protections that limit toxic air pollution.

“This vote reopens a dangerous loophole for the most irresponsible polluters,” said Joanna Slaney, vice president for political and government affairs at Environmental Defense Fund. “These commonsense protections have worked as intended for decades, keeping Americans safe from some of the most toxic air pollution. Overturning these safeguards means more families will breathe unsafe air that causes cancer, heart and lung problems and brain damage in children.”

The resolution, which passed in the Senate on a party-line vote earlier this month, effectively overturns a 2024 rule that provided protections against seven super-toxics, including arsenic, lead and mercury.

Facilities that are “major” sources for the most hazardous pollutants must comply with protective pollution standards based on Maximum Achievable Control Technology (MACT). For decades, EPA policy required major industrial facilities to continue to comply with MACT standards as major sources, even if a source later reduced its emissions below the major source threshold. Because the MACT standards are so effective at reducing air pollution that they often cause industrial facilities to fall below the major source thresholds, this policy prevented increases in emissions up to the threshold. Then in 2020, the Trump administration undermined that policy and created a loophole that would allow many industrial and petrochemical sources to reclassify as area sources and stop complying with MACT standards, ultimately allowing for increases in pollution.

The 2024 rule required all “major” sources of seven hazardous air pollutants to continue complying with MACT regardless of reclassification, consistent with protections from these facilities for over two decades under the “Once In, Always In” policy.

This loophole allows industrial facilities across the country to pollute more and avoid the vital Clean Air Act requirements that are designed to limit the most hazardous air pollution.

With more than 3 million members, Environmental Defense Fund creates transformational solutions to the most serious environmental problems. To do so, EDF links science, economics, law, and innovative private-sector partnerships to turn solutions into action. edf.org