The Toxic Substances Control Act (TSCA), the primary federal law governing industrial chemicals, has historically suffered from major structural limitations that restricted the federal government’s ability to identify and regulate hazardous substances.
When TSCA was first enacted in 1976, it included a grandfather clause that automatically allowed thousands of existing chemicals to remain on the market without undergoing safety review. As a result, widely used PFAS compounds such as PFOA and PFOS were largely exempt from meaningful federal oversight for decades.
The statute also placed a heavy burden on the Environmental Protection Agency (EPA). Before taking regulatory action, the EPA had to demonstrate that a chemical posed an “unreasonable risk” to human health or the environment. At the same time, the agency had limited authority to require manufacturers to provide comprehensive toxicity data. Under the Premanufacture Notice (PMN) system, companies were not required to submit full hazard testing data for new chemicals, while the EPA was required to review each submission within 90 days. In addition, many chemical identities and supporting data were protected under Confidential Business Information (CBI) provisions, further limiting transparency.
These structural constraints significantly weakened TSCA’s regulatory impact. Between 1976 and 2005, the EPA successfully regulated only five chemicals or chemical classes under the statute. One of the agency’s most ambitious actions—the EPA’s 1989 asbestos ban—was largely overturned by a federal court in 1991. Although the court cited flaws in the EPA’s cost–benefit analysis, the ruling emphasized that the agency had failed to satisfy TSCA’s requirement that regulation must be the “least burdensome” approach. This interpretation made future regulatory efforts even more difficult.
These legal limitations were particularly problematic for PFAS, which represent a large and diverse class of chemicals. Many PFAS compounds lacked sufficient toxicity data, and because many were grandfathered under TSCA or shielded by CBI protections, the EPA had limited ability to evaluate or regulate them effectively.
In 2016, Congress attempted to address some of these problems through the Lautenberg Chemical Safety Act, which amended TSCA. The reform strengthened EPA’s authority in several ways, most notably by eliminating the “least burdensome” requirement highlighted in the asbestos case. However, many structural challenges remain.
Most importantly, the revised TSCA still largely evaluates chemicals one substance at a time rather than addressing entire chemical classes. Although the law technically allows regulation of a “category of chemical substances,” risk assessments and regulatory reviews are still conducted primarily on individual chemicals. This approach creates a major regulatory gap: manufacturers can introduce new PFAS variants faster than regulators can evaluate them, a dynamic often referred to as “chemical whack-a-mole.”
As a result, even after the 2016 reforms, significant legal limitations continue to constrain federal chemical regulation and complicate efforts to address PFAS contamination.
(Frank Wang)