This week’s Integrated Risk Information System (IRIS) workshop on the National Research Council’s (NRC) recommendations for improving federal chemical assessments gives the U.S. Environmental Protection Agency (EPA) an opportunity to build on the progress it has already made in creating a sound, more transparent, and objective assessment program. While the agenda for the workshop covers several important areas that deserve attention, it does not include a discussion of two overarching improvements needed to provide a strong foundation for IRIS.
As many of have recognized, EPA has made some important progress, but larger improvements are still needed. In order to successfully address the fundamental issues NRC raised in 2011 and 2014, the Agency must create a more structured process and provide clear guidelines for conducting assessments. In fact, in a recent letter to EPA we suggested that the Agency provide a timeline and outline for plans to address all the high-priority NRC recommendations.
Indeed, a key issue that’s missing from the agenda for the upcoming workshop is discussion of NRC’s recommendation that EPA finalize the draft handbook for how it conducts chemical assessments. Another issue of concern that has yet to be addressed is the need for a protocol for systematic review of chemical-specific assessments, including evaluating and integrating the evidence. ACC highlighted these needed improvements during a recent webinar hosted by the National Capital Area Chapter of the Society of Toxicology to walk through the NRC review of the IRIS process.
Given the importance of these issues, and given the fact that they likely will not be discussed at the workshop, we thought we would bring them to light here.
Key 1: Handbook for chemical assessments
Simply put, EPA needs to finalize its handbook for developing a chemical assessment.
As mentioned earlier, EPA has made some welcome, albeit incremental, adjustments to the way it conducts chemical assessments. While their approach is not flawed in and of itself, it has severely limited stakeholder dialogue by making it unclear what topics and recommendations EPA is addressing at any given time.
ACC believes that establishing clear structural and methodological approaches for developing an assessment could be very valuable and that a more formal, transparent public discussion on the structural and methodological modifications would be useful to the Agency and all stakeholders.
Key 2: Protocol for systematic review
EPA needs to develop a clear protocol for each chemical-specific assessment. This practice should include describing the plans for conducting a literature search and identifying, evaluating, and integrating the evidence. The NRC has specifically recommended that EPA conduct systematic reviews that include protocol development as part of the process. They also recommended that EPA provide a protocol for each IRIS assessment once the chemical-specific systematic review questions are defined.
As part of this protocol, the Agency would need to articulate up front which criteria it has selected to judge the quality and relevance of scientific data in a given assessment. By pre-establishing such criteria, the Agency would make it more feasible for other independent parties to understand, and also duplicate, the choices made by EPA. In other words, “showing your work” and communicating how, precisely, the Agency reached a specific conclusion is just as important as the conclusion itself, and it can help guide others to reach similar conclusions using similar methods (or not, if the case may be).
In addition to developing protocols for all systematic reviews, the Agency should have clear guidelines for deriving relevant toxicity values, prior to the start of a study. This goal is key for any chemical assessment.
In ACC’s view, a single toxicity estimate is insufficient. As recommended by the NRC, in addition to a lower bound (non-cancer) and an upper-bound (cancer) estimate, there should be a central estimate which would help others understand the confidence, or lack thereof, in the study’s conclusions.
A plan for better assessments
Building codes help guide the proper construction of a house. These codes set general standards for builders to follow. Builders also develop a blueprint within these codes to help guide them through each component of construction. Similarly, completing EPA’s IRIS handbook would lay out a set of accepted standards for developing an assessment and for establishing protocols upfront that could serve as a blueprint for individual assessments.
These two recommendations come back to one overall goal: putting objective scientific analysis and transparency at the core of how the federal government evaluates the safety of chemicals. As we have all seen before, a flawed process can lead to unnecessary delays in completing assessments and contribute to a lack of confidence in federal and state chemical management programs and regulations, all of which routinely rely on the assessments. A strong, established plan for developing assessments would help reduce the need for addressing problems after a draft assessment is released and should also shorten the time needed to finalize the assessment.
As NRC has said, the Agency has reached an important milestone for improving IRIS but there is still more work that needs to be done. We are looking forward to participating in this week’s workshop and are committed to continuing working constructively with EPA to strengthen IRIS.