The U.S. Environmental Protection Agency (EPA) announced on November 30, 2021, the release of the National Academies of Sciences, Engineering, and Medicine’s (NASEM) external peer review report of the Office of Research and Development (ORD) Staff Handbook for Developing Integrated Risk Information System (IRIS) Assessments (IRIS Handbook). EPA states that the IRIS Handbook provides standard operating procedures for staffers developing IRIS assessments and includes systematic review approaches that promote consistency and ensure that contributors understand how the assessment components are developed.

The NASEM committee found that the IRIS Handbook “reflects the significant improvements that EPA has made in its IRIS assessment process.” For instance, according to the report, the IRIS Handbook describes the inclusion of “sophisticated, state-of-the-art methods that use systematic evidence maps to summarize literature characteristics for scoping and systematic review methods for hazard identification.” The committee acknowledges that the IRIS program is “clearly helping” to advance the science of systematic review as applied to hazard identification. The report states that the committee “recognizes that EPA faces challenges in implementing many of the methods for the IRIS assessment process and is impressed and encouraged by the progress that the IRIS program has made to date.” The committee suggests that the methods for developing IRIS assessments can serve as a model for other EPA programs implementing systematic review methods.

The committee found that the Handbook does not consistently convey the strengths and advances in methodology for the IRIS assessment process in an even and clear manner, however. The report includes the committee’s recommendations to ensure the IRIS Handbook meets its objectives of providing transparency about the IRIS assessment process and providing operational instructions for those conducting the assessments.