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Bio-based Products vs. Plastic Products: A Critical Look at Life-Cycle-Assessments and Circular Economy
The discussion about sustainable materials has gained significant momentum in recent years. Bio-based products are often praised as the solution to our plastic problems, but a closer look at their life cycle analysis (Life-Cycle-Assessment, LCA) reveals a more nuanced picture. To make informed decisions, we must collect and critically evaluate sustainability data across the entire life cycle.
The Importance of Complete Life-Cycle-Assessments
A Life-Cycle-Assessment is far more than just a comparison of raw materials. It encompasses all phases of the product life cycle: from raw material extraction through production, transport, and use to disposal or recycling. For new bio-based products, this holistic view is particularly important, as only in this way can a data-based differentiation from conventional plastic products be achieved.
The crucial point: Without complete sustainability data across all life cycle phases, sustainability promises are often merely marketing claims. Companies developing bio-based alternatives must transparently demonstrate what environmental impacts their products have in each phase of the life cycle. This includes energy consumption, water use, land use, emissions, and waste streams.
The Reality of Bio-based Production: More Chemistry than "Bio"
A widespread myth is that bio-based products arise exclusively from natural processes. The reality looks different: Bio-based products also frequently require synthetic base materials and complex chemical processes in their production. While Green Chemistry relies on renewable raw materials as a basis, the rest is classical chemistry and process engineering.
This fact does not automatically diminish the sustainability of bio-based products, but makes clear that critical questions must also be asked: Which solvents are used? How energy-intensive are the synthesis processes? Which waste streams are generated? Only with this data can it be assessed whether a bio-based product is more sustainable than its conventional counterpart.
What is Green Chemistry?
Green Chemistry attempts to reduce environmental pollution and save energy, with as environmentally friendly production as possible. Since 1998, twelve principles according to Anastas and Warner describe a Green Chemistry that demands fundamental changes in all three areas:
Process Engineering Perspective:
- Process optimization: Use of catalysts instead of stoichiometric reagents and avoidance of unnecessary intermediate steps
- Energy efficiency: Development of processes that run under milder conditions (lower temperatures/pressures)
- Single-step syntheses: Reduction of multi-step reaction sequences to direct synthesis pathways
Environmental Protection Perspective:
- Waste prevention: Reduction of waste and use of environmentally compatible processes to reduce ecosystem burden
- Toxicity reduction: Reduction of environmental and health burdens from chemicals
- Inherent safety: Selection of substances that minimize the probability of chemical accidents from the outset
- Cradle-to-Cradle vs Cradle-to-Grave approach: Responsibility across the entire product life cycle
Base Materials Perspective:
- Renewable raw materials: Raw materials should be as renewable as possible when this is technically and economically feasible
- Bio-based feedstocks: Development of plant-based ingredients that replace fossil fuel raw materials
- Resource conservation: Long-term sustainable use of natural materials
- Alternative solvents: Replacement of hazardous solvents with environmentally compatible alternatives
Core Principle: Green Chemistry is not an add-on, but a fundamental reorientation of the chemical industry that anchors sustainability in the design phase of molecules, processes, and products - however, it still remains classical chemistry and process engineering with merely "greener" starting materials.
Circular Economy: Big Promises, Unclear Pathways
The assessment of bio-based products in the context of Circular Economy becomes particularly problematic. While the concept of circular economy sounds convincing, we face a fundamental problem with many bio-based materials: We do not have sufficient knowledge of degradation pathways and do not have a proper understanding of the behavior of degradation products in the environment.
These knowledge gaps lead to a paradoxical state: Products are advertised as environmentally friendly because they are biodegradable, yet at the same time we act without a plan regarding the actual environmental impacts. A systematic risk assessment that examines the behavior of degradation products in various environmental compartments (soil, water, air) is often completely missing.
The Microplastics Question: Bio-based Does Not Equal Microplastic-free
A particularly explosive aspect is often overlooked in the discussion about bio-based products: microplastic inputs. Bio-based plastics can also release microplastic particles during their use phase - whether through abrasion, weathering, or mechanical stress. These particles differ chemically from conventional plastics, but their environmental impacts are even less researched.
Looking at the expected quantities, the problem becomes clear: If bio-based products are to achieve a significant market share, we are talking about potential microplastic inputs in the millions of tons range. According to a NABU study, agriculture alone already releases more than 13,000 tons of plastics annually in Germany alone, and a large part of this ends up directly in the soil. With the increase of bio-based materials in agriculture - from mulch films to packaging - these inputs could rise further.
The Federal Environment Agency rightly warns: Plastic - including bioplastics - must never end up in the environment. But the reality looks different: Bio-based materials are often sold with the promise that they are "more environmentally friendly," which can lead to more careless handling.
Micropollutants: The Invisible Danger of Degradation Products
Even more serious is the question of micropollutants that can arise from degradation products of bio-based materials. Just as with conventional plastics, chemical additives or their degradation products can migrate, whereby the health impacts cannot currently be reliably assessed.
The problem is fundamental: "Bio"-plastic contains just as many unknown and partially harmful chemicals as conventional plastic. When these materials are degraded in the environment, degradation products arise whose behavior and toxicity are largely unexplored. These degradation products can:
- Form persistent organic pollutants
- Cause bioaccumulation in food chains
- Enter unpredictable interactions with other environmental chemicals
- Have long-term effects on ecosystems that only show after years or decades
The European Environment Agency has recognized this problem and emphasizes that the environmental compatibility of new plastic products must be critically evaluated. From comparative life cycle assessments, we know that environmental impacts do not significantly improve when raw materials are bio-based instead of fossil-based - the impacts rather shift.
The Status Quo of Bio-based Plastics
Current data clearly show the challenges: According to PlasticsEurope's Circular Economy Report, only 1% of produced plastics came from bio-based materials in 2024. This illustrates that bio-based alternatives are still far from playing a significant role in the circular economy.
At the same time, research institutions like the Fraunhofer Excellence Cluster Circular Plastics Economy are working intensively to develop bio-based plastics that are both biodegradable in the environment and have better recycling properties. But here too it becomes clear: The development of sustainable alternatives is complex and requires a holistic view.
Critical Assessment Without Blanket Rejection
This critical analysis should not mean that bio-based products are to be rejected fundamentally. Rather, it is about creating realistic expectations and asking the right questions. Bio-based materials can certainly be part of the solution, but only if:
- Complete LCA data are available that cover all life cycle phases
- Transparency exists about production processes and chemicals used
- Systematic risk assessments for degradation products are conducted
- Realistic evaluations of Circular Economy properties take place
Necessary Steps for a Data-based Future
To successfully establish bio-based products as sustainable alternatives, we need:
- Standardized assessment methods: Uniform LCA standards specifically tailored to bio-based materials that capture all relevant environmental impacts.
- Long-term studies: Systematic investigations of the degradation behavior of bio-based materials under various environmental conditions over longer periods, including analysis of microplastic inputs and micropollutants.
- Transparent databases: Open databases that make it possible to compare different materials based on complete life cycle data, including data on microplastic release and pollutant potential.
- Integrated risk assessment: Development of evaluation frameworks that systematically capture not only biodegradability but also the impacts of degradation products and emerging micropollutants.
- Microplastic monitoring: Establishment of monitoring systems that continuously capture and evaluate microplastic inputs from bio-based materials.
In Summary: More Critical Differentiation Instead of Blanket Judgments
The future lies neither in unreflective euphoria for bio-based products nor in their blanket rejection.
Instead, we need a critical, data-based approach that honestly evaluates both the opportunities and risks of new materials - including often-overlooked aspects like microplastic inputs and micropollutants from degradation products.
Bio-based products can make an important contribution to a more sustainable future - but only if we develop and evaluate them with the same scientific care that we should also apply to conventional materials. This means: more research, more transparency, and fewer marketing-driven promises.
The challenge lies in developing innovative materials that are not only sustainable on paper, but whose sustainability is measurable and verifiable across the entire life cycle. We must not make the mistake of creating new environmental problems while trying to solve old ones. Only in this way can we ensure that the next generation of materials contributes to solving our environmental problems, instead of shifting or multiplying them.
