SCHF v. EPA 943 F.3d 397 revokes nexus risk assessment in TSCA

In Safer Chemicals, Health Families v. EPA 943 F.3d 397 (9th Cir. 2019), in which the plaintiffs challenged the US Environmental Protection Agency’s (EPA) Toxic Substances Control Act (TSCA) Risk Assessment Rule, the Court referred to the historical legislation emphasizing the role of TSCA as a gap-filling law. TSCA was never meant to regulate “discharges, emissions, ambient air, or consumer products,” neither in 1976, when TSCA was first enacted, nor 40 years later, when it has been substantially modified.

TSCA’s gap-filling role underlies what is known as the regulatory nexus approach to the assessment of existing chemicals in which the EPA’s Office of Chemical Safety and Pollution Prevention (OCSPP) has adjusted the scope of risk assessments by excluding environmental exposure pathways covered by other statutes administered by the EPA. or regulatory programs. Each of the 10 initial risk assessments and final scoping documents for the 20 high priority chemicals provided a lengthy rationale for this approach, which stated in part:

In its TSCA Section 6(b) risk assessments, the EPA coordinates action on certain exposure pathways and risks within the jurisdiction of other laws or regulatory programs administered by the EPA. Specifically, the EPA is exercising its TSCA powers to tailor the scope of its risk assessments, rather than focusing on environmental exposure pathways addressed under other EPA-administered statutes or regulatory programs or on risks that could be eliminated or reduced to a sufficient extent by the measures taken. under other laws administered by the EPA.

The rationale included explicit legislative text that further supported the regulatory nexus approach. Under TSCA §6(b)(4)(D): “The administrator shall, no later than six months after the commencement of a risk assessment, publish the scope of the risk assessment to be conducted, including including hazards, exposures, conditions of use, and potentially exposed or susceptible subpopulations that the administrator expects to consider…”. The EPA also cited TSCA §9(b)(1), which states that “[t]The administrator coordinates the actions […] with actions taken under other federal laws administered in whole or in part by the Administrator. The word “actions” has been interpreted broadly by the EPA to include both risk assessment and risk management. But that was then. What is the current status of the regulatory nexus approach under new EPA leadership?

During an October 27, 2021 oversight hearing into the House Energy and Commerce Committee’s implementation of TSCA, OCSPP Deputy Administrator Dr. Freedhoff readily acknowledged in written testimony that “TSCA no is not intended to supersede laws such as the Clean Air Act or the Safe Drinking Water Act. But in that same sentence, she pivoted to categorically state that “TSCA requires us to assess exposures that occur when people breathe air or drink water containing the chemical being assessed.”

Scope documents issued by OCSPP further confirm Dr. Freedhoff’s testimony. Previous scoping documents have included a section on exposure pathways and hazards addressed by other statutes administered by the EPA. However, more recent application documents, including for example DINP, do not include this section.

It would seem that the regulatory link, at least in the context of risk assessment, is dead. But could it resurface in the development of risk management rules? That remains to be seen. We will have to wait for the OCSPP to propose a chemical-specific risk management rule to assess whether the EPA adopts the regulatory link, relying on other laws or EPA programs to manage the risks that were identified in the chemical-specific risk assessment.

Martin E. Berry