Oct. 10, 2014
Framework to Guide Assessment of Chemical Alternatives

Chemicals used in consumer products and industrial processes have elicited concerns in recent years about health or environmental impacts, prompting manufacturers, retailers, and regulators to develop methods for evaluating potentially safer chemical substitutes. Although a number of assessment tools exist, they reflect a range of different priorities, such as protecting workers, the end user, or the environment.

A new report from the National Research Council describes a decision framework for comparing chemicals in terms of human health and ecological risks that is more uniformly applicable for a diverse set of users while remaining flexible enough to be tailored to the specific decision being made. The framework draws on the strengths and common characteristics of existing assessment approaches, but also includes several advancements: problem formulation and scoping, comparative exposure assessment, and evaluation of physicochemical properties.

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. The report also highlights how modern information sources such as computational modeling can supplement traditional toxicology data in the assessment process.

Many decisions involved in selecting a viable chemical alternative will be value-driven and context-dependent, the report says. Defining and documenting the goals, principles, and decision rules guiding the assessment is important, to make explicit how uncertainty and trade-offs are resolved.