We interviewed and collected experience from over 40 designers and manufacturers of bio-based and biodegradable materials. 95% of interviewees recognised the value of LCA for comparison, but 67% felt that LCA standards showed bias towards fossil materials. We studied this bias and suggest three areas in which sustainability assessment, and in particular LCA, inherently favours fossil-based materials.
Incomparability: Differences in assumptions, scope and attribution often lead to incomparability between fossil and bio-based or biodegradable materials. Standards should ensure comparability but even when fully adopted, we observed significant differences. 83% of our respondents believed that LCA regulation is currently unsatisfactory.
Implicit bias: Common impact categories and assessment methods were developed during fossil-based material incumbency, meaning categories in which bio-based or biodegradable materials perform well, for example microplastics, are often not included in established methods. Fossil materials are able to show their advantages whereas bio-based and biodegradable materials are not.
End-of-life treatment: Modeling compostability in LCA typically relies on generic data, which often requires manual adjustments. Most models do not include emission to soil and water, and often only include greenhouse gas impact categories, leading to inconsistency and implicit bias.
To address these problems, we suggest it may be necessary to reframe comparative LCA and develop a bias-free methodology to allow comparison between fossil materials and bio-based or biodegradable materials. We suggest a new set of impact categories, and specific guidance on the comparison of fossil and bio-based or biodegradable materials.