Qualitative Approach to Comparative Exposure in Alternatives Assessment

William Greggs, Thomas Burns, Peter Egeghy, Michelle R Embry, Peter Fantke, Bonnie Gaborek, Lauren Heine, Olivier Jolliet, Carolyn Lee, Derek Muir, Kathy Plotzke, Joseph Rinkevich, Neha Sunger, Jennifer Y Tanir, Margaret Whittaker

Most alternatives assessments (AAs) published to date are largely hazard-based rankings, thereby ignoring potential differences in human and/or ecosystem exposures; as such, they may not represent a fully informed consideration of the advantages and disadvantages of possible alternatives. Building on the 2014 US National Academy of Sciences recommendations to improve AA decisions by including comparative exposure assessment into AAs, the ILSI Health and Environmental Sciences Institute's Sustainable Chemical Alternatives Technical Committee, which comprises scientists from academia, industry, government, and nonprofit organizations, developed a qualitative comparative exposure approach. Conducting such a comparison can screen for alternatives that are expected to have a higher or different route of human or environmental exposure potential, which, together with consideration of the hazard assessment, could trigger a higher-tiered, more quantitative exposure assessment on the alternatives being considered, minimizing the likelihood of regrettable substitution. This article outlines an approach for including chemical ingredient- and product-related exposure information in a qualitative comparison, including ingredient parameters and product-related parameters. A classification approach was developed for ingredient and product parameters to support comparisons between alternatives as well as a methodology to address exposure parameter relevance and data quality. The ingredient parameters include a range of physicochemical properties that can impact routes and magnitude of exposure, whereas the product parameters include aspects such as product specific exposure pathways, use information, accessibility, and disposal. Two case studies are used to demonstrate the application of the methodology. Key learnings and future research needs are summarized. This article is protected by copyright. All rights reserved.