Insights from Life Cycle Assessment to Inform Chemical Substitution, Alternatives Assessment and Safe and Sustainable-by-Design

Designing chemicals and pharmaceuticals with optimal
properties
yet minimal negative effects on humans and the environment remains
challenging. Chemical substitution enables us to address this challenge
but requires significant methodological advancements and testing to
become mature and more widely adopted worldwide. We use insights from
life cycle assessment (LCA) to explore and synthesize synergies for
advancing substitution approaches, including alternatives assessment
and comparative safe and sustainable-by-design (SSbD). We screen boundary
conditions for LCA and substitution and use an illustrative case study
on comparing two sets of pest control options to discuss learnings
for addressing challenges toward a mature chemical substitution field.
For some aspects, LCA provides strong inspiration to inform developments
of substitution approaches, such as using a common functional comparison
basis, aligning assessment metrics and units, and considering full
life cycles to avoid burden shifting. For other aspects, LCA is less
informative and substitution requires additional developments. This
includes systematic overviews of possible context-specific alternatives,
mapping of chemical, material, and other functions, more detailed
life cycle inventories, and rapid-screening assessment methods. Combining
learnings from LCA with ways to address remaining challenges will
help advance chemical substitution to support the objectives of UNEP’s
Global Framework on Chemicals and other policy instruments for a broader,
much needed sustainability transition.