Turning regrettable substitutions into informed choices: Empowering chemical alternative assessment through life cycle perspective

The production and consumption of chemicals generate pollution and unintended impacts. Although chemical alternative assessment is a practical approach, inadequate quantitative data through life cycle thinking and a lack of practical substitution information limit effective substitution practices. This study presents a workflow that incorporates the Chemical Life Cycle Collaborative (CLiCC) modeling tool to address data gaps by providing (1) chemical hazards in both qualitative and quantitative contexts and (2) an assessment of the life cycle impacts of alternative chemicals. The workflow incorporates function-based substitution analysis aimed at determining the optimal amount of substitution for a given product application. This workflow provides a replicable approach to chemical alternative assessment, enabling the integration of useful tools for informed decision-making in lower- risk and lower-impact chemical substitution. A case study on five groups of chemicals, including cleaning agents, solvents, preservatives, plasticizers and paint strippers, validated the tool's applicability and potential for improvement. For instance, in the evaluation of alternative solvents, certain options were identified as feasible because of their lower climate change impact. However, concerns regarding problem shifting emerged from the qualitative narrative, as these alternatives demonstrated comparably higher impacts on ecosystem quality and Eco-indicators. In addition, the findings from the sensitivity analysis highlight the practicality of using substitution factors to identify greener alternatives with similar chemical properties and product applications. This approach facilitates effective equal-mass substitutions, minimizes process interruptions and supports decision- makers in achieving favorable environmental and practical outcomes. Overall, our study demonstrates the importance of life cycle thinking, which provides rich contextual information for substitution decisions and helps to prevent regrettable substitutions.