- within Environment, Criminal Law and Employment and HR topic(s)
- in United States
- with readers working within the Environment & Waste Management and Utilities industries
The U.S. Court of Appeals for the Fifth Circuit has granted the
U.S. Environmental Protection Agency (EPA) another 90-day extension
in its litigation over the Biden administration's revised
evaluation of 1,4-dioxane (1,4-DX) under the Toxic Substances
Control Act (TSCA). This pause, requested by EPA, is intended to
allow continued review of the chemical's cancer risk
assessment. Union Carbide Corp. v. EPA, No. 24-60615 (5th
Cir., filed September 30, 2025).
In 2020, during the final days of the first Trump administration,
EPA concluded that 1,4-DX poses unreasonable risk to workers in 13
of 24 evaluated conditions of use. But the 2020 evaluation also
concluded that the chemical poses no unreasonable risk as a
byproduct in consumer products. In a 2024 evaluation, the Biden EPA
reversed course, concluding that 1,4-DX poses unreasonable risk
across its uses, including byproduct exposures previously deemed
safe. Industry groups challenged the revised assessment, arguing
that EPA's use of a linear model to evaluate cancer risk
deviates from scientific consensus and leads to overly stringent
regulations.
EPA's current review centers on this cancer risk methodology.
In May 2025, Nancy Beck, EPA's Principal Deputy Assistant
Administrator for Chemical Safety, estimated the review would take
12 to 24 months. By June, she truncated that estimate to 12 months
while noting that it was EPA's goal to complete the review
within six months. Beck now reports progress toward that goal,
including hiring a contractor to review relevant studies and
reports.
But the government shutdown that began on October 1, 2025, will
likely delay progress—potentially significantly. According to
EPA's contingency plan, TSCA programs are not
included in the list of significant agency activities that will
continue during the funding lapse. The contractor EPA engaged may
also be limited in its capacity to work during the shutdown per the
terms of its agreement with EPA. Historical precedent—namely
the 34-day shutdown during President Donald Trump's first
term—suggests even short shutdowns can significantly disrupt
EPA operations by compounding existing backlogs in chemical
evaluations and regulatory timelines. Thus, even if the government
is funded in the near term, a ripple effect caused by halted agency
projects could reverberate through EPA after the shutdown
ends.
Manufacturers and users of 1,4-DX should therefore anticipate
potential regulatory tightening and prepare for extended
uncertainty in TSCA implementation timelines. Strategic engagement
with EPA and legal counsel is advised to navigate evolving
compliance obligations and risk assessments.
The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.
