Trump epa questions its own authority to update air pollution rules based on new science

The Trump administration’s EPA is reconsidering whether the agency has the legal authority to revise air pollution regulations multiple times when new scientific evidence reveals greater health risks—a move that could severely limit the agency’s ability to protect public health from toxic chemicals.

The controversy centers on ethylene oxide, a colorless gas that the EPA discovered in 2016 was 30 times more carcinogenic than previously thought. This revelation led to stricter regulations in 2024 requiring medical sterilizers and chemical plants to dramatically reduce emissions of the cancer-causing compound, which is linked to lymphoma and breast cancer. The updated rules were projected to cut the number of residents exposed to unacceptable cancer risks from 90,000 to just 3,000 near chemical plants alone.

However, chemical industry groups have argued that the EPA lacks authority under the Clean Air Act to conduct multiple “residual risk reviews” for the same pollutant, even when decades pass or new health data emerges. Trump EPA officials have now signaled they may agree with this interpretation, potentially preventing the agency from responding to future scientific discoveries about the dangers of nearly 200 regulated air pollutants from thousands of industrial facilities.

Environmental advocates warn this could “kneecap” the EPA’s mission, leaving the agency powerless to act even when new evidence shows chemicals are far more toxic than originally understood. Recent air monitoring in Louisiana’s Cancer Alley, for example, found ethylene oxide concentrations much higher than companies reported, creating unacceptable cancer risks for local communities. If the EPA accepts the industry’s legal argument, it might be unable to strengthen protections even in such clear-cut cases of public health threats.