Alternatives Assessment Frameworks: Research Needs for the Informed Substitution of Hazardous Chemicals

Given increasing pressures for hazardous chemical replacement, there is growing interest in alternatives assessment to avoid substituting a toxic chemical with another of equal or higher concern. Alternatives assessment is a process for identifying, comparing and selecting safer alternatives to chemicals of concern (including those in materials, processes or technologies) on the basis of their hazards, performance, and economic viability. The purpose of this substantive review of alternatives assessment frameworks is to identify consistencies and differences in methods, and to outline needs for research and collaboration to advance science policy practice.The review compares methods used in six core components of these frameworks: hazard assessment; exposure characterization; life cycle impacts; technical feasibility evaluation; economic feasibility assessment; and, decision-making. Alternatives assessment frameworks published from 1990 to 2014 were included. Twenty frameworks were reviewed. The frameworks were consistent in terms of general process steps but there were some differences identified in the endpoints addressed. Methodological gaps were identified in the exposure characterization, life cycle assessment, and decision-analysis components. Methods for addressing data gaps remain an issue. Greater consistency in methods and evaluation metrics is needed but also sufficient flexibility to allow the process to be adapted to different decision contexts. While alternatives assessment is becoming an important science policy field, there is a need for greater cross-disciplinary collaboration to refine methodologies in support of the informed substitution and design of safer chemicals, materials, and products. Case studies can provide concrete lessons to improve alternatives assessment.