As reported in our February 25, 2022, blog item, the U.S. Environmental Protection Agency (EPA) announced on February 25, 2022, the proposed Toxic Substances Control Act (TSCA) New Chemicals Collaborative Research Program. 87 Fed. Reg. 10784. On March 10, 2022, EPA the posted the draft document entitled “Modernizing the Process and Bringing Innovative Science to Evaluate New Chemicals Under TSCA.” The Office of Chemical Safety and Pollution Prevention (OCSPP) proposes to develop and implement a multi-year collaborative research program focused on approaches for performing risk assessments on new chemical substances under TSCA. EPA will hold a virtual public meeting April 20-21, 2022, to seek individual input. Written comments on the draft document are due April 26, 2022.

According to the draft document, prior to developing this research plan, the Office of Pollution Prevention and Toxics (OPPT) developed the following problem formulation statement:

PROBLEM STATEMENT:

Using the best available science involves OPPT’s use of methods, approaches, and tools to evaluate new chemicals prior to their entrance into US commerce, and refining and updating them where appropriate. Any changes should align with statutory deadlines, be operational in a data poor environment, make effective use of new data sources and approaches, and be transparent to the extent practicable given that TSCA [confidential business information (CBI)] may be used in the development of these approaches.

The draft document states that the following vision statement provides the foundational concepts that need to be included in the research to address the problem statement.

VISION STATEMENT:

Continue to evolve OPPT’s use of new and existing methods, approaches, and tools for evaluating new chemicals under TSCA that typically lack specific information (i.e., are data poor) on human health and environmental risks through the use of innovative science.

According to the draft document, OPPT is collaborating closely with the Office of Research and Development’s (ORD) Center for Computational Toxicology and Exposure (CCTE) and Center for Public Health and Environmental Assessment (CPHEA) to develop and implement the research plan. Additionally, EPA will consult internal and external partners critical to delivery of the research plan for input and research contributions. The proposed research is focused on five areas. EPA notes that some activities are already underway while others are new and have not yet started.

1. Update and Refine Chemical Categories:

• Problem: Currently 56 TSCA categories, last updated 2010;
   
• Approach: Systematically define chemical categories and analogues for read-across using structural (and other) boundaries; physical-chemical properties; structural alerts for hazard, fate, exposure, and/or functional uses; existing hazard data; and/or in vitro mechanistic and toxicokinetic data from new approach methodologies (NAM); and
   
• Expected Outcome: This will increase the efficiency of new chemical reviews and promote the use of the best available data to protect human health and the environment.
   

2. Develop and Expand Databases Containing TSCA Chemical Information:

• Problem: Existing TSCA information is not computationally accessible or easily searchable;
   
• Approach: Extract and curate available TSCA CBI study information; continue extraction and curation of physical-chemical property, environmental fate, hazard, and exposure information (non-CBI) in ORD databases; and map information in ORD databases to standardized reporting templates and store in an International Uniform Chemical Information Database (IUCLID); and
   
• Expected Outcome: The TSCA CBI information will be combined with publicly available sources to expand the amount of information available, enhancing chemical reviews and enabling efficient sharing of chemical information across EPA. Safeguards for CBI will be maintained as appropriate in this process.
   

3. Develop and Refine Quantitative Structure-Activity Relationships (QSAR) and Predictive Models for Physical-Chemical Properties, Environmental Fate/Transport, Hazard, Exposure, and Toxicokinetics:

• Problem: Currently used models are not always publicly accessible, easy to update with additional chemicals, or the best performing for all chemistries;
   
• Approach: Develop and update QSAR and predictive models using existing data and curated data from Research Area #2; and evaluate models to determine the best suite for use by OPPT for regulatory purposes; and
   
• Expected Outcome: Updated models that reflect the best available science, increased transparency, and a process for updating these models as science allows.
   

4. Explore Ways to Integrate and Apply NAMs in New Chemical Assessments:

• Problem: Reduction in the use of vertebrate animals in accordance with TSCA Section 4(h); many premanufacture notice (PMN) submissions are data poor; and amended TSCA requires affirmative determination regarding unreasonable risk;
   
• Approach: Develop and evaluate a suite of in vitro NAMs for informing new chemical evaluations; and use mechanistic and toxicokinetic in vitro NAMs to inform and refine chemical categories in Research Area #1; and
   
• Expected Outcome: A suite of NAMs that could be used by external stakeholders for testing and data submissions under TSCA, as well as informing and expanding new chemical categories.

5. Develop a TSCA New Chemicals Decision Support Tool to Modernize the Process:

• Problem: Searching, collating, and integrating data for new chemical assessments is inefficient and costly;
   
• Approach: Build proof of concept software workflow that integrates all data streams in a new chemical risk decision context; and
   
• Expected Outcome: A decision support tool that will efficiently integrate all the data streams (e.g., chemistry, fate, exposures, hazards) into a final risk assessment and transparently document the decisions and assumptions made. This will facilitate the new chemicals program tracking decisions over time and evaluating consistency within and across chemistries.
   

Next Steps

EPA will hold a virtual public meeting April 20-21, 2022, to seek individual input. Written comments on the draft document are due April 26, 2022. According to the draft document, later in 2022, EPA plans to engage its Board of Scientific Counselors (BOSC), a federal advisory committee, for peer review. EPA also intends to issue a Federal Register notice announcing the BOSC meeting and to open a docket for public comments. EPA states that it will solicit additional peer review and public comment at multiple points in the development and implementation phases of the research. Although the peer review schedule may be adjusted as necessary in the future, at this time, OPPT anticipates the following:

• Status update, discussion of challenges, possible revisions to initial plan (year 3); and

• Completion of initial data collection and analyses and preliminary versions of new models and approaches (years 5-6).
   

EPA will publish the data and approaches from the research efforts in the open scientific literature. EPA will also implement outreach through appropriate mechanisms, including scientific societies, state and tribal communications, internationally through the Organization for Economic Cooperation and Development (OECD), and other mechanisms. EPA will hold public meetings to receive input and enhance transparency.

Commentary

EPA is to be commended for initiating these research areas. As EPA’s own commentary notes, each of the five areas is in need of updating and modernizing, and chemical innovation under TSCA will be advanced as a result as the desired outcomes are achieved.