Guidelines for Sustainable Bioplastics
Biobased content is the amount of biobased carbon in the material or product as fraction weight (mass) or percent weight (mass) of the total organic carbon in the material or product. ASTM Method D6866-05 is the US government approved method for determining the renewable/biobased content of biobased products.
Biobased material(s) are organic material(s) in which the carbon comes from contemporary (non-fossil) biological sources.
Biodegradable plastics are plastics that can decompose into carbon dioxide, methane, water, inorganic compounds, or biomass via microbial assimilation (the enzymatic action of microorganisms). To be considered biodegradable, this decomposition has to be measured by standardized tests, and take place within a specified period time, which vary according to the “disposal” method chosen.
The American Society of Testing and Materials (ASTM) has created definitions on what constitutes biodegradability in various disposal environments. Plastics that meet ASTM D6400, for instance, can be certified as biodegradable and compostable in commercial composting facilities. In Europe the equivalent standardized test criteria is EN 13432.
In the US, there is a biodegradability standard for soil (ASTM D5988), a biodegradability test standard for marine and fresh water (ASTM D6692 and D6691), one for wastewater treatment facilities (ASTM D5271), and one for anaerobic digestion (ASTM D 5511). Other countries have similar standards and certifications. Belgium is unique in offering “The OK Compost” mark, which guarantees that the product can be composted in home composting systems.
While many bioplastics are indeed certifiable as compostable in commercial compost facilities, not all can be home composted and not all are biodegradable in the marine environment. Furthermore, a number of fossil fuel-based polymers are certified biodegradable and compostable. Biodegradability is directly linked to the chemical structure, not to the origin of the raw materials.
Bioplastics are plastics in which 100% of the carbon is derived from renewable agricultural and forestry resources such as corn starch, soybean protein, and cellulose. Bioplastics are not a single class of polymers but rather a family of products which can vary significantly from one another. They differ from traditional plastics, which are derived from fossil fuels or non-renewable carbon. Not all bioplastics are biodegradable and not all biodegradable plastics are bioplastics.
Organic material(s) are material(s) containing carbon based compound(s) in which the carbon is attached to other carbon atom(s), hydrogen, oxygen, or other elements in a chain, ring, or three dimensional structure.