EPA’s failure to properly implement TSCA puts lives at risk

In the 40 years between enactment of the original Toxic Substances Control Act (TSCA) in 1976 and its 2016 amendments, EPA regulated less than 1% of the existing chemicals on the market. EPA was even unable to ban cancer-causing chemicals like asbestos, part of the reason Congress updated TSCA to make it easier for regulators to ban or restrict harmful chemicals and protect public health.

But the promise of the 2016 amendments has not kept up with the reality. PRHE and our partners, several of whom are former EPA scientists, analyzed what’s gone wrong with the implementation of TSCA in a paper published today in Environmental Science & Technology.

EPA isn’t following the “best available science”

We compare EPA’s first 10 chemical risk evaluations (high priority chemicals due to high risk of health harm) completed under amended TSCA to the “best available science” required by the law to evaluate risks to public health. Based on our assessment, EPA has failed to implement the new law properly. This leaves people, especially the most vulnerable TSCA was designed to protect, exposed to harmful chemicals.

What TSCA requires EPA to do

To determine if a chemical poses an “unreasonable risk,” amended TSCA requires EPA to evaluate existing chemicals using the “best available science,” and account for risks to “potentially exposed or susceptible subpopulations (PESS)” including children, pregnant people, and workers without considering cost. It also requires EPA to regulate chemicals determined to pose an “unreasonable risk” “to the extent necessary so that the chemical substance no longer presents such risk”.

While the 2016 amendments were a significant update, many critical implementation decisions, including how to assess and apply the “best available science” were left to EPA to determine, therefore making it vulnerable to political interference and scientific integrity concerns. As amended TSCA preempts states from acting on chemicals EPA is evaluating, or has regulated, it makes the stakes of these implementation decisions even higher.

We found EPA’s risk evaluations systematically underestimated human health risks of chemical exposures, particularly vulnerable populations by:

  1. excluding conditions of use and exposure pathways
  2. not considering aggregate exposure and cumulative risk
  3. not identifying all potentially exposed or susceptible subpopulations, and not quantifying differences in risk for susceptible groups
  4. not addressing data gaps, and
  5. using flawed systematic review approaches to identify and evaluate the relevant evidence

We discussed the public health implications and recommendations for each area that EPA is falling short on. These include:

  • EPA should revise its first 10 risk evaluations to incorporate all conditions of use and include exposure pathways within the jurisdiction of other EPA statutes and continue to do so in future risk evaluations
  • EPA should combine quantitative exposure estimates across exposure pathways and settings including chemical uses not subject to TSCA such as food packaging, and assess the impacts of exposure to multiple chemical mixtures and structural drivers of health
  • EPA should explicitly name what qualifies populations as susceptible in its risk evaluations and prepare a comprehensive methodology to identify PESS and quantify their risks consistently within and across its risk evaluations
  • EPA must apply its reporting and testing authorities under amended TSCA to require chemical manufacturers to provide the data, including toxicity studies, necessary to perform its ongoing and future risk evaluations
  • EPA should follow the National Academies of Science Engineering and Medicine recommendations and implement a systematic review method compatible with empirically-based existing methods and aligns with authoritative definitions of a systematic review, including the Institute of Medicine

The 2016 amendments to TSCA were implemented after decades of struggling with a law that was widely identified as weak and ineffective. Amended TSCA provided an opportunity for health and environmental protection from chemical pollution, but right now that’s not what’s happening.

It is essential for EPA to improve TSCA implementation to ensure equitable, socially just safeguards to public health.


About the authors

Nick Chartres, PhD is the Associate Director of the Science & Policy team at PRHE, which monitors and analyzes federal, state, and local chemical policy, including EPA’s implementation of the Toxic Substances Control Act. He has extensive experience in the use of systematic review methods and leads PRHE’s work to ensure the best available science is used for policy decision making.

Swati Rayasam, MSc is a Science Associate on the Science & Policy team at PRHE. She has been one of the leads on the team for PRHE’s work to ensure EPA’s implementation of the Toxic Substances Control Act protects the health of communities disproportionately impacted by toxic chemical pollution. She has expertise in federal and international policy, exposure science, community-guided science, science translation/communication, toxics, infectious disease, and water, sanitation and hygiene (WASH).