In the article, Going, Going, Gone? Regulatory Nexus in TSCA Risk Evaluations of Existing Chemicals, I discussed the concept of regulatory nexus in the context of Toxic Substances Control Act (TSCA) risk evaluations, in which the U.S. Environmental Protection Agency (EPA) had “tailored the scope of risk evaluations by excluding environmental exposure pathways addressed under other EPA-administered statutes or regulatory programs.” EPA relied, in part, on TSCA section 9(b), in which “The Administrator shall coordinate actions taken under [TSCA] with actions taken under other Federal laws administered in whole or in part by the Administrator” to address risks associated with the chemical substance. “[O]ther federal laws” include, for example, the Safe Drinking Water Act and the Clean Air Act, among others. Under the current EPA administration, however, I concluded that regulatory nexus is dead. 

At the time of the previous article, EPA had not yet issued any proposed risk management rules. It was, therefore, uncertain as to whether a flicker of regulatory nexus remained in the context of risk management. EPA’s most recently proposed risk management rule on methylene chloride - which includes scores of conditions of use - permits us to explore this question.  

Remarkably, EPA devotes a mere four paragraphs to analyzing TSCA section 9(b). EPA makes several points:

1. If the Administrator decides not to rely on other statutory authorities to address the risks identified in a TSCA risk evaluation, section 9(b) requires the Administrator to “consider … all relevant aspects of the risk … and a comparison of the estimated costs and efficiencies of the action to be taken [under TSCA] and an action to be taken under such other law to protect against such risk.” 

2. EPA acknowledges that other environmental statutes do regulate methylene chloride exposure, but do not regulate “occupational and consumer exposures” to methylene chloride. Instead, these other statutes (e.g., RCRA, CAA, CWA) focus primarily on environmental releases. 

3. Unlike other environmental statutes, TSCA would address “the primary exposures and unreasonable risk to consumers, bystanders, workers, and occupational non-users.” 

4. Thus, no statute other than TSCA could eliminate or reduce “to a sufficient extent” the unreasonable risk from methylene chloride as identified in the risk evaluation. 

EPA also determined no other federal law not administered by EPA would prevent or reduce the unreasonable risk from methylene chloride to a sufficient extent.

Thus, with regard to managing the unreasonable risk from methylene chloride, all roads lead to TSCA section 6(a). Regulatory nexus in the context of risk management, just as in the context of risk evaluation, is dead.   

Is methylene chloride unique? Will subsequent risk management rules embrace regulatory nexus, at least to some extent and under this current Administration? Despite the adage, “never say never,” I think the answer is more akin to “never.”