EPA Publishes A Working Approach for Identifying Potential Candidate Chemicals for Prioritization

On September 28, 2018 EPA released the approach it will use to identify chemicals that could be included in the next group of risk evaluations under the Toxic Substances Control Act (TSCA).  The approach is documented in the publication A Working Approach for Identifying Potential Candidate Chemicals for Prioritization (A Working Approach). EPA also announced that the Agency will be looking for input from the public on which chemicals should be prioritized for risk evaluation and which chemicals may be low priorities under TSCA.   By December 2019, EPA must designate at least 20 chemical substances as High-Priority for risk evaluation and 20 chemical substances as Low-Priority for which risk evaluation is not currently warranted.

A Working Approach lays out EPA’s near-term approach for identifying potential chemicals for prioritization, the initial step in evaluating the safety of existing chemicals under TSCA.  The Agency notes that it expects its approach for identifying candidates for prioritization to evolve over time as it develops expertise in identifying chemicals to enter prioritization, as well as in conducting prioritization and risk evaluations.

EPA’s working approach is to primarily look to the 2014 Work Plan for high-priority potential candidates.  The Agency explains that it generally intends to consider the three factors described below for selecting potential chemicals for prioritization.

  • In selecting chemicals as potential candidates for prioritization EPA expects to consider overarching Agency priorities. This may include, but is not limited to, a chemical or group of chemicals that are priorities for the Agency, including chemicals that other EPA program offices have deemed a priority for their program and suitable for current prioritization. In addition, EPA is committed to engaging and collaborating with partner federal agencies prior to and during the prioritization process.
  • Quantity and Quality of Information. EPA intends to consider the quantity and quality of information when identifying potential candidate chemicals for prioritization and risk evaluation.
  • Work Load. To address workload issues, EPA could use diverse approaches to consider current expertise or facilitate the analysis of candidate chemicals. For example, EPA could identify potential candidate chemicals that share certain characteristics with the first 10 chemical substances undergoing risk evaluation, 15 such as solvents, since focusing on the solvents remaining on the 2014 Work Plan would take advantage of the expertise developed on the six solvents currently undergoing risk evaluation (e.g., development of exposure scenarios).

In identifying potential candidates for low priority chemical designation, A Working Approach explains that EPA will use the best available science.  The document reports that EPA may identify substances from multiple sources, including one or more of the following chemical information resources:

  • EPA’s Safer Chemical Ingredients List;
  • EPA’s Chemical Assessment Management Program; and
  • Organization for Economic and Co-Operation Development Screening Information Data Sets assessment documents.

A Working Approach states that EPA intends to preferentially select CAS numbers that represent discretely defined structures, which can be more confidently associated with information on hazard, conditions of use, and exposure.

The document also includes a longer-term risk-based strategy for managing the larger TSCA chemical landscape which, according to the TSCA Inventory, is composed of more than 40,000 active chemicals. This longer-term approach proposes parsing chemicals into “bins” that can be used to inform multiple activities and priorities throughout EPA, including within the TSCA program.  In the near future, EPA will open a public docket to accept comments on this longer-term strategy.  In addition, the Agency plans to hold a public meeting on the strategy in early 2019.

EPA will also open 73 chemical-specific public dockets, one for each of the remaining chemicals on the 2014 TSCA Work Plan.  Additionally, there will be a general docket open for the public to suggest chemicals for risk evaluation that are not on the Work Plan.  Through these dockets, the public will have the opportunity to submit use, hazard, and exposure information on these chemicals.  The Agency will use this data to inform TSCA prioritization and risk evaluation for these chemicals.