On December 20, 2021, EPA released a draft TSCA Systematic Review Protocol. In its announcement on the new Protocol, the Agency explained that the Protocol will strengthen EPA’s approach to reviewing and selecting the scientific studies that are used to inform TSCA Risk Evaluations and ensure that EPA has the best tools under TSCA to protect human health and the environment. The draft protocol comprises nearly 700 pages.
The draft Protocol notes that EPA’s Office of Pollution Prevention and Toxics (OPPT) applies systematic review principles in the development of its Risk Evaluations of existing chemicals. It provides specific systematic review approaches which they use for identifying and evaluating evidence for the hazard and exposure assessments that support Risk Evaluations. OPPT added that the draft Protocol responds to key recommendations received from the National Academies of Sciences, Engineering, and Medicine (NASEM).
The Protocol was developed in response to NASEM’s critique that EPA had not previously documented how TSCA prioritization and problem formulation relate to the TSCA Systematic Review. The Protocol aligns the TSCA prioritization and scoping processes with the steps of the Protocol. In addition, the Protocol defines how EPA’s systematic review efforts will identify data gaps and data needs in the Risk Evaluations process. OPPT explains that identifying these data gaps and data needs will provide the Agency with the information it needs “to strategically exercise TSCA authorities to require testing or information collection for use in TSCA prioritization and Risk Evaluation.”
The Protocol reports that for the 20 high-priority substances currently undergoing Risk Evaluation and substances undergoing manufacturer-requested Risk Evaluation, EPA has implemented a new, unified literature search process. This process, as described in the Protocol, uses chemical identifiers to maximize the capture of relevant literature, which in turn provides consistency and efficiency to the literature search. In addition, OPPT announced that the Protocol includes new methods to reduce bias and improve evaluation through the use of calibration exercises and data evaluation training for reviewers. This is a response to NASEM recommendations, SACC comments, and public comments.
In addition, the Protocol includes a description of the evidence integration process. A step that was not part of the 2018 TSCA systemic review document. This addition was also made in response to recommendations by the NASEM and the SACC. OPPT explains that the Protocol’s evidence integration approach relies on methods related to those in EPA’s IRIS Handbook.
The draft protocol will undergo peer review by at a meeting of the SACC on April 19-21, 2022. OPPT noted that the agency will use this feedback to further improve the document. The date, time for the public peer review virtual meeting will be announced on the SACC website.