Union Carbide Asks Court to Review Supplemental 1,4-Dioxane TSCA Risk Evaluation
Chemical company Union Carbide has asked a federal appeals court to review the US EPA’s supplemental TSCA risk evaluation for 1,4-dioxane and its determination that the solvent poses an unreasonable risk to human health.
Filed in the US Court of Appeals for the Fifth Circuit on 4 December, the petition for review marks a rare legal challenge following a TSCA risk evaluation, which is not on its own considered a final agency action subject to judicial review. Typically, stakeholders must wait until the EPA finalises a TSCA risk management rule before they can bring a legal challenge to an underlying risk evaluation.
In its petition for review, Union Carbide, a subsidiary of Dow Chemical Company, said the supplemental risk evaluation of 1,4-dioxane completed in November can be challenged in court because it includes a "final order" that withdraws ‘no unreasonable risk’ determinations the EPA made for several conditions of use (COUs) in its original 2020 evaluation of the solvent.
Those Trump-era determinations were accompanied by a TSCA section 6(i)(1) order that the agency considered to be "final agency action", and which drew a legal challenge from NGO petitioners at the time.
In turn, the supplemental evaluation’s withdrawal of those 2020 orders last month is itself a final agency action that can be reviewed by a court, Union Carbide said.
The company did not specify in its petition whether it wants a full court review of the supplemental risk evaluation, reinstatement of the earlier ‘no unreasonable risk’ findings or another remedy.
1,4-dioxane risk findings
1,4-dioxane is used in certain commercial and industrial applications, including in the manufacture of other substances, as a processing aid and in adhesives and sealants. It also can appear as a byproduct of the manufacturing process for ethoxylated surfactants, resulting in contamination in some cosmetic and cleaning products.
The solvent's presence as a contaminant in such products and their potential to contaminate surface water helped to trigger the EPA’s supplemental review, following regulatory scrutiny in New York and California.
At least two Union Carbide facilities – one in Louisiana and one in Texas – reported releases or disposal of 1,4-dioxane in recent years, according to the EPA’s Toxic Release Inventory.
November’s TSCA supplemental risk evaluation found unreasonable risk associated with nearly every use of 1,4-dioxane, including its manufacture and disposal, six processing applications, 15 industrial and commercial uses and in five consumer applications.
These determinations, if left unaltered, would lead the EPA to impose risk management measures to mitigate risks so that they are no longer ‘unreasonable’.
The case is Union Carbide Corp v US EPA, et al.