EPA Takes Critical Step Towards Strengthening Science Used in Chemical Risk Evaluations
WASHINGTON (Dec. 20, 2021) - Today, in support of the Biden-Harris Administration’s commitment to making evidence-based decisions and developing policies and programs that are guided by the best available scientific data, the U.S. Environmental Protection Agency (EPA) released a draft Toxic Substances Control Act (TSCA) Systematic Review Protocol. The protocol will strengthen EPA’s approach to reviewing and selecting the scientific studies that are used to inform TSCA chemical risk evaluations and ensure that EPA has the best tools under TSCA to protect human health and the environment.
“We must build our chemical risk evaluations on strong science in order to provide meaningful protections for all communities from dangerous chemicals,” said Michal Freedhoff, Assistant Administrator for the Office of Chemical Safety and Pollution Prevention. “The protocol released today was developed in close collaboration with EPA’s Office of Research and Development and incorporates the feedback of the National Academies of Sciences, Engineering, and Medicine to improve our process for using high quality, best available scientific data and studies in TSCA risk evaluations.”
In 2018, the previous Administration released the Application of Systematic Review in TSCA Risk EvaluationsIn 2019, EPA contracted the National Academies of Sciences, Engineering, and Medicine (NASEM) to review the approach included in that 2018 document. The February 2021 report from the NASEM TSCA Committee found that the previous systematic review process contained incomplete and hard to follow documentation, did not meet the criteria of “comprehensive, workable, objective, and transparent” and did not meet the standards of systematic review methodology. NASEM recommended that EPA revise its approach, incorporating components from existing methodologies, including EPA’s Integrated Risk Information System (IRIS) program.
In response to recommendations made by the NASEM as well as comments received from the TSCA Scientific Advisory Committee on Chemicals (SACC) and the public, EPA has significantly updated the TSCA systematic review process and developed a systematic review protocol.
The draft TSCA Systematic Review Protocol released today includes key recommendations received from NASEM on the Application of Systematic Review in TSCA Risk Evaluations. It is a product of collaboration with the Office of Research and Development’s IRIS program, and will continue to be improved by public feedback, examination of the recent NASEM report on the ORD Staff Handbook for Developing IRIS Assessments, and evolution of the state of the science in the field of systematic review.
Additionally, the draft protocol will undergo peer review by at a meeting of the SACC on April 19-21, 2022, and the agency will also use this feedback to further improve the document. The date, time, and registration instructions, including information on making oral comments during the meeting, for the public peer review virtual meeting will be announced on the SACC website by early March 2022.
The 2018 Application of Systematic Review in TSCA Risk Evaluations was not used for EPA’s 20 ongoing risk evaluations and will not be used again. The TSCA Systematic Review Protocol released today reflects the current approaches for the ongoing TSCA risk evaluations for the 20 high-priority designated chemicals, manufacturer-requested risk evaluations, and supplemental evaluations of asbestos and 1,4-dioxane. Details specific to the manner in which the protocol has been used for each of these chemical risk evaluations are included in the appendices.
In this draft TSCA protocol, EPA streamlines the data evaluation of human health hazards by enabling the use of recent and future IRIS systematic reviews. This also allows more seamless updates of literature evaluation into the TSCA systematic review evaluations based upon the interoperability of software platforms being utilized in both IRIS and TSCA systematic review evaluation programs.
The draft protocol also includes new methods to reduce bias and improve evaluation consistency between reviewers and across chemicals. These improvements include coordinated data evaluation training and calibration exercises for reviewers, the development of additional internal evaluation guidance, and improvement of evaluation forms. As recommended by NASEM, data quality evaluation under this draft protocol would involve two levels of review, a primary review and a secondary quality-control review for each study. In cases where the two reviewers are not in agreement, an explicit conflict resolution step is included. Also, in response to a variety of commenters, the draft protocol no longer includes a quantitative/weighted scoring system for data evaluation. Rather, it applies ordinal rankings to guide the qualitative categorization of high, medium, low, or critically deficient for each data evaluation metric.
EPA is accepting comments on the draft protocol in docket EPA-HQ-OPPT-2021-0414 for 60 days until February 18, 2022.