Contributed by David Dorman, Professor of Toxicology at North Carolina State University and Chair of the National Research Council committee
Growing concerns about the health and environmental impacts associated with some chemical products and processes—think bisphenol A or flame retardants--have prompted a number of national, state, and local governments, manufacturers, and retailers to develop methods for finding safer chemical substitutes. There are now a number of alternatives assessment tools in existence, which allow users to compare proposed chemical substitutes before they are swapped into a product or process. But these existing assessment tools reflect a range of different priorities, whether the focus is on protecting workers, the environment, the end users of products, or other interests. What this report sets out to do is provide a more universally applicable decision framework for comparing chemicals in terms of human health and ecological risks would benefit a wide range of alternative assessment users.
A report released last week from the National Research Council sets out to meet that need. Drawing on the strengths and common characteristics of existing assessment approaches, the report presents a 13-step framework that includes several advancements: problem formulation and scoping, comparative exposure assessment, and evaluation of physicochemical properties. These attributes make the framework applicable for a diverse set of users while remaining flexible enough to be tailored to the specific decision being made.
In addition to hazard assessments, the framework incorporates steps for life cycle thinking—which considers possible impacts of a chemical at all stages including production, use, and disposal—as well as steps for performance and economic assessments.
Many decisions involved in selecting a viable chemical alternative will be value-driven and context-dependent, the report notes. Defining and documenting the goals, principles, and decision rules guiding the assessment is important, to make explicit how uncertainty and any trade-offs are resolved.
If potential chemical alternatives fail to meet the established criteria—or come with an unacceptable trade-off such as prohibitive cost—research and innovation is needed to design new chemicals, or identify other ways to solve the problem. The report finds that making safety and ecological considerations an integral part of chemical design would help identify best alternatives as early as possible. The report also highlights how modern information sources such as computational modeling can supplement traditional toxicology data in the assessment process. In coming years, it will be critical for the scientific community to embrace the challenge and advantages of using novel data streams in the alternatives assessment process. The report also suggests that de novo design of new alternatives to meet the desired safety and functional needs is an opportunity for innovation. This approach to alternatives embodies green chemistry principles by intentionally designing chemicals that are safer. Future efforts are needed to develop principles or tools that support the benchmarking and integration of high throughput data on chemical effects, especially in the context of different regulatory requirements.
David Dorman is Professor of Toxicology at North Carolina State University and Chair of the National Research Council committee that authored the report A Framework to Guide Selection of Chemical Alternatives. The American Chemistry Society is well represented among the report’s authoring committee and staff: Committee members Peter Beak, Eric Beckman, Niger Greene, Helen Holder, Jim Hutchison, Carol Henry, Adelina Voutchkova-Kostal, and Martin Wolf, and study co-director Kate Hughes.
The complete report is available for free PDF download, along with a Report brief (4-page lay summary). In addition, a report webinar featuring a presentation and Q&A session with David Dorman and other committee members is scheduled for Friday, October 24 at 12:30 EDT; please register to attend.
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