Department of the Environment

About us | Contact us | Publications

Settlements Header ImageSettlements Header ImageSettlements Header Image

Publications archive - Waste and recycling

Disclaimer

Key departmental publications, e.g. annual reports, budget papers and program guidelines are available in our online archive.

Much of the material listed on these archived web pages has been superseded, or served a particular purpose at a particular time. It may contain references to activities or policies that have no current application. Many archived documents may link to web pages that have moved or no longer exist, or may refer to other documents that are no longer available.

Biodegradable Plastics - Developments and Environmental Impacts

Nolan-ITU Pty Ltd
Prepared in association with ExcelPlas Australia
October, 2002

Solutions, Future Directions and Research

Development of Australian Standards and Testing

For the successful introduction of degradable plastics into Australia it is essential that for any new application that the following are clearly identified:

For this to be achieved it will be necessary to establish a national framework for standards and testing. This could be based upon appropriate international standards.

Life-Cycle Assessment

Further work is also required to understand the fate and consequence of recalcitrant residues such as small aromatic compounds, small polymer particles and other residues in the environment from the degradation and incomplete degradation of biodegradable plastics.

Full Life Cycle Assessment (LCA) work on the production, use and disposal of biodegradable polymers, with reference to conventional polymers, should be carried out to determine the real environmental and social benefits and impacts of their introduction into a range of applications. This would cover:

Comprehensive LCA data and analysis would assist in the development of appropriate policy.

Minimisation of Impact on Reprocessing

The introduction of competing products to those which are currently recovered and reprocessed via sorting facilities, such as some plastics bags, HDPE and PET bottles, should only occur after industry is fully satisfied that failsafe sorting systems are available. As with other plastics, biodegradable polymers could be given a unique polymer identification code to minimize confusion and assist in sorting.

Research on the impacts of the incorporation of biodegradable plastics into established plastics reprocessing systems may be required. Small variations in the ratio of biodegradable to nonbiodegradable material could significantly alter the quality of the end material and failure rate in uses reliant on strength. Further research would allow for appropriate policies, labelling, sorting procedures and mechanisms to be developed to minimise the impact on this industry.

Determination of Appropriate Disposal Environments

Extensive consultation with the product supply chain and potential disposal chain, including sorting, reprocessing, and composting bodies, will be necessary before the widespread introduction of biodegradable products that may impact on excisting recycling and composting systems. This could be carried out in a similar manner to the National Packaging Covenant and incorporate COAG (Council of Australian Governments) principles.

Composting as a planned disposal route, particularly for film and sheet, should only occur once a system is in place to identify these materials as distinct from non degradable products. One possible solution is to introduce a unique standard colour (i.e. bright lime green) so they can be easily differentiated from non-biodegradable plastics in a composting environment. This way non-biodegradable plastics can still be manually removed while the biodegradable plastics can be left in situ.

Unique colour-based identification of biodegradable plastics would also assist plastic recyclers in identifying those plastics that are not compatible with mechanical recycling processes. A parallel identification system involving a logo such as the 'Compost OK' mark would allow consumers to identify these products.

There does not appear to be any significant impediment, however, to the introduction of biodegradable products destined for landfill disposal, such as garbage bags, landfill covers, and non-recycled shopping bags, provided that they meet the appropriate testing standards.

Education

With the introduction of biodegradable plastics into the consumer packaging market, effective education is essential. It will be important to educate the public that biodegradable plastics do not degrade instantaneously to avoid the potential to increase the incidence of littering.

In addition, clear disposal routes must be identified and available to consumers to appropriately manage this waste stream. For example, to stipulate that an item should be disposed of to the consumer's green organics bin which is destined for a commercial composting operation would result in issues where residents are not provided with these services.