vor 5 Jahren

05 | 2010

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Opinion Sustainability

Opinion Sustainability Counts Through the Life Cycle By Heeral Bhalala Coordinator, Sustainable Biomaterials Collaborator Institute for Local Self-Reliance Washington, DC , USA Fossil-fuel-derived plastics are non-renewable, often threaten public health, have devastating impacts on marine life, and increase reliance on imported fossilfuel-based feedstocks in many countries. The development of bioplastics holds great promise to mitigate many of these sustainability problems by offering the potential of renewability, biodegradation, and a path away from harmful additives. They are not, however, an automatic panacea. Harvesting of forest biomass can be done in ways that jeopardize the health of the forest and ecosystem. Modern industrial agriculture creates a host of health, environmental, social issues including the use of genetically modified organisms (GMOs) in the field, toxic pesticides, high fossil fuel energy use, and the loss of family farms. Farming can also degrade water and soil quality and endanger natural habitat and biodiversity. Increased demand for agricultural products may well exacerbate problems posed by modern agriculture while increasing pressure on ecologically sensitive land and raising food security concerns. The manufacture, use and discard of products made from bioplastics can also result in hazardous emissions, particularly if the bioplastic is mixed with fossil fuel-based chemicals. While many bioplastic products are certified compostable, challenges remain in developing the collection services and the composting infrastructure to ensure products are actually composted at the end of their intended use. At the same time, some bioplastic products may be recyclable but similarly lack the necessary infrastructure, while posing concerns for existing recycling systems. The Sustainable Biomaterials Collaborative (SBC) is a network of organizations working together to spur the introduction and use of biomaterials that are sustainable from cradle to cradle. The Collaborative seeks to advance the development and diffusion of sustainable biomaterials by creating sustainability guidelines, engaging markets, and promoting policy initiatives. It is broadly focused on the entire lifecycle of biomaterials from production in the fields, to green manufacturing, to product use, and recycling or composting at the end of product life. We define sustainable biomaterials as those that: (1) are sourced from sustainably grown and harvested cropland or forests, (2) are manufactured without hazardous inputs and impacts, (3) are healthy and safe for the environment during use, (4) are designed to be reutilized at the end of their intended use, such as via recycling or composting, and (5) provide living wages and do not exploit workers or communities throughout the product lifecycle. Starting at the Source An assessment of the sustainability of bioplastics begins at the source, looking at how feedstocks are grown and harvested. While bioplastics are made from a wide variety of agricultural and forest-based materials, most of the bioplastics available today are derived from corn and other commodity crops, crops that have clear and significant impacts on our natural environment. But agriculture can also improve water and soil health, provide refuge and food for wildlife and increase biodiversity and economic prosperity for farmers, their families and communities. The SBC is working to further develop and implement an innovative market-based approach that allows bioplastic users to support environmental stewardship on agricultural lands. The Working Landscapes Certificates (WLC) program is currently focused on corn-based plastics, but could expand to other feedstocks. WLCs are a purchasable offset for companies presently using bioplastics that want to support sustainable farming practices. This payment is used to financially support farmers who agree to raise the crop under prescribed sustainability criteria. For corn this means not using GMO seed, eliminating carcinogenic chemical and atrazine use, and other practices that promote better environmental quality. The program is now poised for major expansion. Negotiations are nearly complete with a major national company to grow the WLC program over five-fold this year with more growth in later years. 58 bioplastics MAGAZINE [05/10] Vol. 5

Opinion Making the Product By paying attention to the principles of green chemistry, manufacturers can increase process safety to protect worker health, and minimize hazardous emissions into the environment. Biobased producers could avoid problematic blends that contain large quantities of petroleum plastic, thus easing reclamation of the product. Avoiding persistent, bioaccumulative, and other toxic chemicals is important. Consider use of nanomaterials with caution as not all have been comprehensively tested for health or safety impacts. Design for Recovery Bioplastics are just another burden on the landfill unless they are recovered for recycling or composting. In the US, waste incineration is broadly opposed, while anaerobic digestion for methane recovery is becoming more widely accepted. Without the technology and infrastructure in place to handle discarded biobased products, bioplastics are likely to end up trashed rather than recovered. While the composting infrastructure is developing, systems for recycling bioplastics are virtually non-existent and have many challenges to their widespread implementation. For example, who will capitalize the equipment to sort PLA from PET? Will compostable plastic bags contaminate the recycling of conventional polyethylene bags? Product labeling is a critical issue to inform citizens how best to handle products once used. Biodegradation in the marine environment is also increasingly being recognized as important. Industry Challenge Developing the technology and markets for sustainable bioplastics will require time. The Collaborative has defined a progression of intermediate steps towards reaching sustainable biobased products (see sidebar ‘Steps to Best Practice‘). We encourage companies to evaluate their current practice and make public commitments toward these goals. Please visit our website for more information. Steps to Best Practices for Each Life Cycle Stage 1) Biological Feedstock Production a) Eliminate hazardous chemicals of concern b) Avoid use of genetically modified seeds c) Conserve, protect and build soil d) Conserve nutrient cycles e) Protect air and water access and quality f) Promote biological diversity g) Reduce impacts of energy use h) Reduce transportation impacts i) Develop and certify a comprehensive sustainable agriculture plan j) Protect workers 2) Processing and Manufacturing a) Support sustainable feedstock production b) Reduce impacts of energy use c) Avoid problematic blends and additives and encourage recycling d) Maximize process safety and minimize hazardous emissions e) Continuous improvement f) Protect workers 3) Product Distribution and Use a) Reduce quantity used b) Avoid unhealthy exposures c) Create opportunities for sustainability education d) Label material content e) Prefer local 4) End of Product a) Ensure safe and rapid biodegradation b) Design product for recycling or composting c) Producer and converter industry participate in planning for complete life d) Protect workers Source: Guidelines for Sustainable Bioplastics,, 2009 bioplastics MAGAZINE [05/10] Vol. 5 59

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