A new report document from the BBIA (the Bio-Based and Biodegradable Industries Asociation) provides an explanation of Biodegradable and Compostable Polymer Materials.
The report gives further information on the process of biodegradation and it relevance to polymer materials. Such knowledge is critical in the bioplastics sector with two key characteristics explained as being important in determining whether and when the biodegradability of a bioplastic is useful:
- To be of practical value the rate of biodegradation has to be appropriate to the timescale of the end use/application involved.
- The environment in which the bioplastic finds itself at the end of life. Sometimes bioplastics will break down in certain conditions but not in others (e.g., a material might biodegrade in compost or soil, but not in a marine environment). A few biopolymers will biodegrade under a wider range of environments, for example polyhydroxy alkanoates (PHAs), but these are not a panacea – property and processing characteristics can still restrict potential end uses.
The report also gives further details on the process of composting, annaerobic digestion and soil degradation with reference to the biodegradability of polymer materials. The report also highlights the challenges of achieving biodegradation of biopolymer materials in freshwater and marine environments. The lack of biodegradability of ‘oxo-degradation’ materials is also explained.
Overall the report clarifies many points around the use of biobased materials. The key summary points are as follows:
- Biodegradability as a property of a material should always be qualified with reference to the particular environment(s), end uses and relevant timescales.
- Standards and/or protocols are largely in place for aerobic composting and anaerobic digestion, as well as soil, freshwater and marine biodegradation. These define appropriate testing environments, timescales and criteria for the useful deployment of biodegradable materials.
- There is a need to simplify the messaging on biodegradability and compostability via a clearer labelling system – an initiative that is already underway in the UK.
- Bioplastics are, for now, niche products, best suited to a range of specific applications where their environmental credentials offer real benefits over fossil-fuel alternatives.
More information about the BBIA can be found here: https://bbia.org.uk/