The U.S. Environmental Protection Agency’s (EPA) controversial chemical hazard assessment program, Integrated Risk Information System (IRIS), is under fire. In recent years, it has been widely criticized for being scientifically flawed and too slow. IRIS, one of the most important programs EPA uses to assess chemical safety, serves as a leading source of health risk information for other federal, state, and international regulatory bodies. The program has been repeatedly criticized for failing to consistently meet high standards of scientific accuracy and transparency in order to ensure high quality, reliable assessments. In December 2011, Congress directed the agency to improve its risk assessments. The National Research Council (NRC),1 under the auspices of the National Academy of Sciences, is currently conducting a comprehensive examination of the IRIS assessment development process.
Without incorporating the necessary changes to data evaluation and weight of evidence and causal determinations, IRIS assessments will continue to suffer from many of the very same critical scientific shortcomings that have plagued the program. Specifically, Plumbing Manufacturers International (PMI) has called on EPA to allow for public participation early on in the IRIS process, to strengthen the peer review process, and to stop the selective use of data.
PMI applauds the NRC for its in-‐depth examination of the IRIS assessment process and EPA’s participation in the review. As part of its evaluation, the NRC is expected to make recommendations to improve the scientific and technical performance of the IRIS Program. The NRC will also examine current methods for weighing evidence analyses and recommend approaches for gauging the scientific evidence for chemical hazard identification, which is crucial to strengthening the scientific foundation of IRIS.
To its credit, the EPA has committed to adopting a series of recommendations made by the National Academy of Sciences, including streamlining presentation of its analyses, making its toxicity evaluations more uniform and incorporating multiple data sets. PMI is encouraged by the fact that top EPA officials overseeing the IRIS program announced their support, during the September 2012 NRC meeting, for additional changes to the IRIS program, including gathering public input before assessments are drafted and generating new data for analyses.
PMI is carefully monitoring EPA’s development of its IRIS assessments for hexavalent chromium and nickel. In the case of hexavalent chromium, the IRIS assessment will serve as the basis for setting the national drinking water standard for this chemical.
PMI has been specifically concerned with EPA’s selective use of data and some assumptions that it has made to plug gaps in the scientific evidence in its Draft Toxicological Review of Hexavalent Chromium and not relying on the most up-to‐date and best available science.
In 2009, ToxStrategies initiated a multi-million dollar research program to develop new data that EPA could use to assess the risk that hexavalent chromium poses from low-level, environmentally relevant exposure through drinking water.
The research represents the work done a group of researchers from more than a dozen institutions, including several universities, expands on the 2008 studies conducted by the National Toxicology Program and will help fill in missing data from EPA’s draft IRIS hex chrome risk assessment. The ToxStrategies research is now being published in peer-reviewed scientific journals and being shared with EPA staff.2
Every plumbing manufacturer supports safe drinking water. However, if EPA were to set a new drinking water standard for hex chrome without fully understanding and accepting all relevant scientific findings, including the ToxStrategies work, the use of hex chrome as used in the plumbing manufacturing process could be significantly restricted in the future.3
PMI was pleased when EPA announced that it was postponing the completion of its Draft Toxicological Review for hex chrome until the spring of 2013. PMI strongly recommends that the EPA include all the new research studies developed by ToxStrategies in the agency’s draft Toxicological Review of Hexavalent Chromium.
- EPA’s IRIS system needs an overhaul. More work is needed to get the IRIS program back on track and ensure that the agency produces scientifically sound assessments that are capable of guiding public health decisions.
- We applaud EPA’s recent statements that the agency is committed to making significant changes to its chemical hazard assessment program.
- Given the potential impact of a new hex chrome drinking water standard on thousands of businesses, consumers and water utilities, the acknowledged data gaps in EPA’s draft IRIS hex chrome risk assessment must be filled and include the best available science.
- EPA must include all the new research studies developed by ToxStrategies in the agency’s draft Toxicological Review of Hexavalent Chromium.
1 The National Research Council (NRC) Committee to Review the Integrated Risk Information System Process held its first meeting on Sept. 17–18, 2012. The next meeting will be held in December.
2 ToxStrategies is expected to complete research Mode of Action Cancer Research Project for Ingestion of Hexavalent Chromium by the end of 2012.
3 Chrome-plated plumbing fixture surfaces are metallic chrome, not hex chrome, and provide durable chemical and abrasion resistant surfaces that are easy to keep clean on faucets, showerheads, and tub spouts.