In response to critical feedback, notably from the National Research Council (NRC), the EPA has announced that it will revise its Integrated Risk Information System (IRIS), the primary tool the Agency uses to assess the impact of chemicals on human health, which, in turn, supports regulatory and other policy actions.  New elements in the program include enhanced transparency and opportunities for public input early in the assessment process, more-rigorous peer reviews, a revised weight-of-evidence approach, and “stopping rules” that restrict inclusion of studies that are published late in the assessment process. 

NRC report

In 2011, the NRC reported that EPA’s use of IRIS in assessing the risks posed by formaldehyde “was not prepared in a logically consistent fashion, lacks clear links to an underlying conceptual framework, and does not sufficiently document methods and criteria used to identify evidence for selecting and evaluating studies.” 

Recommendations were directed at both the formaldehyde assessment specifically and the IRIS program in general.  For example, the NRC recommended that the EPA more clearly articulate why it selected certain studies to use in the assessment.  Also, regarding weight-of-evidence, the NRC said the EPA needs to explain why certain elements (such as consistency) were emphasized in synthesizing the evidence.

Areas of improvement

The EPA says it will comply with NRC’s recommendations to improve IRIS assessments in three areas.

• Science 
  • Use a new document structure that is clearer, more concise, and more systematic.
  • Adopt systematic review methods and information management tools (as they are developed) for study selection and analysis.
  • Adopt data-integration or weight-of-evidence approaches (as they are developed) to develop overall findings.
  • Strengthen practices for peer review and protections against conflicts of interest.
• Productivity
  • Conduct a needs assessment to better understand client needs for IRIS assessments.
  • Focus staff attention on a smaller overall number of assessments, and ultimately increase efficiency and output of the program.
  • Restrict reliance on new data after peer review to those studies that have an impact on the credibility of an assessment’s conclusions, for example, a “strong new study that indicates a heretofore undiscovered health effort, or a strong new study that might change, in either direction, a major conclusion.”
• Development
  • Before initiating an assessment, release a planning and scoping study and convene a public meeting focused on identifying the scientific information available for the chemical under assessment.
  • In the early stages of development, release a literature search strategy, evidence tables, exposure-response figures, and, as appropriate, information on anticipated key scientific issues for the chemical.
  • Release the draft assessment and draft peer review charge for public comment and hold a public meeting.  In some cases, revise the draft assessment and peer review charge after hearing the public’s comments about these materials.

  Industry response

  The American Chemistry Council (ACC) commended the Agency for its commitment to “make much needed improvements” to IRIS.

  “Improved dialogue and a willingness to engage with outside experts, in particular, will help speed up the process of implementing a transparent, science-based chemical assessment program,” says the ACC.

  Click here for information about EPA’s IRIS enhancements.