Expert Report

Review of EPA's Integrated Risk Information System (IRIS) Process (2014)

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At the request of Congress, this study evaluates EPA's progress in responding to recommendations from the National Research Council for improving the Integrated Risk Information System (IRIS) process, which is the program responsible for developing toxicologic assessments of chemical contaminants in the environment. The study finds that the changes to the IRIS process that EPA has proposed and implemented to various degrees constitute substantial improvements. If current trajectories are maintained, inconsistencies identified in the report are addressed, and objectives still to be implemented are successfully completed, the IRIS process will become much more effective and efficient in achieving the program's basic goal of developing assessments that provide an evidence-based foundation for ensuring that chemical hazards are assessed and managed optimally. Read these report highlights to learn more

Key Messages

  • The changes to the IRIS process that EPA has proposed and implemented to various degrees constitute substantial improvements.
  • Materials and examples provided by EPA indicate that the agency is incorporating systematic-review principles, which should strengthen the IRIS process. Systematic review is defined as "a scientific investigation that focuses on a specific question and uses explicit, prespecified scientific methods to identify, select, assess, and summarize the findings of similar but separate studies."
  • In response to general recommendations from the NRC, EPA has implemented a new document structure that streamlines the assessments; made greater use of evidence tables and graphic displays that improve clarity and transparency; added a standard preamble to all assessments that describes the IRIS process and its underlying principles; drafted a handbook that provides a more detailed description of the IRIS process; formed chemical assessment support teams (CASTs) to oversee the assessment-development process and ensure consistency among assessments; established tracking procedures; and implemented several initiatives to increase stakeholder input.
  • EPA has made progress on many of the specific steps in the IRIS process, but some additional improvements could be made. Details are provided in the report.
  • To ensure that the IRIS program provides the best assessments possible into the future, EPA should (1) update assessment methods on a continuing fashion; (2) systematically identify and address inefficiencies in the program; and (3) continually evaluate whether its IRIS teams have the appropriate expertise and training.