Chemicals in Consumer Products

Life Cycle-based Chemical Alternatives Assessment

About this project

In response to the thousands of potentially toxic chemicals used in commerce, the European Chemicals Agency outlined a “Strategy to promote substitution to safer chemicals through innovation”. Chemical alternatives assessment (CAA) is a suitable tool for chemical substitution, but lacks indicators for impacts along chemical and product life cycles, leaving important tradeoffs unassessed. This project therefore aims to develop and illustrate a new approach called “Life Cycle Based Chemical Alternative Assessment (LCAA)” that quantifies and compares exposure and life cycle impacts consistently and efficiently over the main life cycle stages.

People

Lei Huang (huanglei@umich.edu)

Peter Fantke (pefan@dtu.dk)

Michael Overcash (mrovercash@earthlink.net)

Olivier Jolliet (ojolliet@umich.edu)

Keywords

Chemical alternatives assessment (CAA), life cycle assessment (LCA), life cycle impacts, exposure quantification, chemical substitution, hazardous chemicals

Project Summary

We systematically evaluate the scope of CAA and identify key elements for quantifying exposure and life cycle impacts relevant for any given chemical-product application. We use a tiered approach to assess for different scopes indicators, starting points and assessment outcomes. We start with the chemical use and disposal stage and related consumer exposure, and systematically broaden the assessment scope via exposure and related impacts over the supply chain of the target chemical and the alternatives, the whole chemical life cycle, to finally include the entire product or process application life cycle (Table 1).

Table 1: Tiered approach for including exposure and life cycle impacts into the process of chemical alternatives assessment.

At each assessment scope level, cumulative near-field (i.e. in the vicinity of consumers or workers) and far-field (i.e. via the outdoor environment) transfers and related human and ecological exposures are linked to chemical mass used in given product applications or related environmental emissions, and toxicity hazard information to characterize toxicity impacts over the respective assessment scope (e.g. chemical life cycle), based on an integrated framework that aligns various exposure settings in a single assessment matrix (the PiF framework). Other impacts (e.g. climate change) are screened for their contributions to overall product-related impacts per product application type.

We test our approach in a case study of plasticizer in vinyl flooring and outline future research needs to operationalizing a Life Cycle-based Alternatives Assessment (LCAA). It is demonstrated that the chemical hazard potentials, exposure, and chemical mass in the given product application need to be combined to allow for an overall screening-level ranking of alternatives for substituting a given target chemical.

Comment: Comparison of exposure doses of alternatives to DEHP in vinyl flooring. RfD: reference dose, HQ: hazard quotient. The ratio of the mean daily dose to the RfD yields the hazard quotient. Across 10 potential alternatives to DEHP, the non-phthalate plasticizers DEHA and 97A show similar daily doses as DEHP, but have hazard quotients up to a factor of 30 lower due to higher RfD values. On the other hand, TXIB, ATBC and DEHPA have RfDs similar as DEHP, but show much higher hazard quotients due to higher daily doses. These results demonstrate that it is not sufficient to look at hazard potential or exposure alone when doing chemical alternative assessments.

Publications

Peer-reviewed journal articles

Fantke, P., Huang, L., Overcash, M., Griffing, E., Jolliet, O. (2019). “Toward life cycle based alternatives assessment (LCAA)”. In preparation

White paper

Published conference proceedings and abstracts

Presentations

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