Tennessee Passes Law That Requires ‘Best Science Available’ for PFAS Regulations

Senate Bill 880 was introduced by Senator Shane Reeves in February, was passed by the Senate on April 3, and was later passed by the House of Representatives on April 7. Governor Bill Lee signed the bill into law on April 21.

Under the law, starting July 1, an agency cannot adopt a rule establishing numeric criteria or limitations for a substance, mixture, or chemical related to drinking water, water pollution control, hazardous substances, contaminated site remediation, air quality, or solid or hazardous waste handling unless the regulatory action is based upon the “best available science.” With respect to human health, “the best available science” must also establish a direct link, based on generally accepted scientific practice, to manifest bodily harm in humans. The law defines “best available science” as science that is “reliable, unbiased, and reasonably applies to the agency’s rule,” “[m]aximizes the quality, objectivity, and integrity of information,” and “[i]nvolves the use of supporting studies conducted in accordance with generally accepted scientific or technical practices utilizing data collected by generally accepted methods or best available methods.” The law only applies to agency rules that are more stringent than any applicable federal regulation or adopted in the absence of a federal regulation.

One point of contention during the passing of this law was whether to remove a provision in the original draft that barred the use of “supporting studies” published in journals that charge “publication or submission fees to authors.” The intent of the provision was to exclude “junk science” that may be published in journals requiring fees but that do not undergo robust peer-review. However, during the hearings, stakeholders testified that even respected journals charge administrative fees for publishing, and therefore the provision was unnecessary. As a result, the original draft was amended to remove that provision.

Importantly, the standard set forth by the law resembles that under Federal Rules of Evidence 702, 703, and Daubert, the goal of which is to keep junk science out of the court room and ensure that expert opinions are based on reliable methodology and supported by peer-reviewed studies, among other things.

Advocates for the law believe that these new requirements will promote the use of best available science in promulgating regulations and will help agencies avoid falling prey to public policy overreaction or pressure from fast-developing media coverage of emergent PFAS and other chemicals without properly vetting the information. Critics, on the other hand, argue that the law will prohibit the government from responding to real-time emergencies because oftentimes technology and science take years to develop. They also argue that the law will limit the government’s ability to control and mitigate the known risks associated with PFAS.

This law also reflects the direction that federal PFAS regulation may be trending. As discussed in a previous client alert, the federal government may soon change the way that the US Environmental Protection Agency carries out chemical risk evaluations of PFAS, which could effectively reduce federal regulations of PFAS.

Additionally, similar legislation is being considered in West Virginia, although the measure did not advance during the legislature’s 2025 session. The bill has faced stiff opposition from local scientists, arguing that it would “establish an insurmountable burden of proof for agency rulemaking that is out of step with scientific practice.”

Stay informed on legislative developments that may affect your industry operations and compliance strategies. The Consumer Products group at ArentFox Schiff is available to answer questions about how your company can address risks of PFAS regulation enforcement both in the contractual and litigation contexts. Please feel free to reach out to the authors or any attorney on those teams.