Photo Credit: C.Launay/Race for Water 2015.
Problems with bioplastics and oxo-degradable plastics.
The biodegradability of matter can be explained as follows: Biodegradation is a chemical process during which microorganisms (and possibly organisms also) that are available in the environment convert materials into natural substances such as water, carbon dioxide, and compost (no artificial additives are needed). The process of biodegradation depends on the surrounding environmental conditions (e.g. location, temperature and/or moisture content), on the material and on the application.
‘Biobased’ does not equal ‘biodegradable’
The property of biodegradation does not depend on the resource basis of a material but is rather linked to its chemical structure. In other words, 100 percent biobased plastics may be non-biodegradable, and 100 percent fossil based plastics could potentially be biodegrade.
Benefits of bioplastics
Bioplastics are driving the evolution of plastics. There are two major advantages of biobased plastic products compared to their conventional versions: they save fossil resources by using biomass which regenerates (annually) and provides the unique potential of carbon neutrality. Furthermore, biodegradability is an add-on property of certain types of bioplastics. It offers additional means of recovery at the end of a product’s life cycle.
Problems with bioplastics
Widespread adoption of products labelled “biodegradable” will not significantly decrease the volume of plastic entering the ocean or the physical and chemical risks that plastics pose to marine environment.
Misconceptions are being feed to the public en mass, concerns about impacts on marine environments grows at an alarming rate. Complete biodegradation of plastics only occurs in conditions that are rarely, if ever, met in a marine environment, with some polymers requiring industrial composters and prolonged temperatures of above 50°C to disintegrate. There is also some limited evidence suggesting that labelling products as biodegradable increases the public's inclination to litter.
What can you do
Switch from single use plastic to reusable plastic. Insist on recyclable types of plastic only, the type that has no dangerous chemicals added, and then, most importantly, make absolutly sure that it reaches a recycling facility capable of dealing with it. Make absolutly sure it does not end up in the oceans.
More damning evidence
UNEP Executive Director Achim Steiner said, "Recent estimates from UNEP have shown as much as 20 million tons of plastic end up in the world's oceans each year. Once in the ocean, plastic does not go away, but breaks down into microplastic particles. This report shows there are no quick fixes, and a more responsible approach to managing the lifecycle of plastics will be needed to reduce their impacts on our oceans and ecosystems."
In recent years, concern has grown over microplastics (particles up to 5mm in diameter, either manufactured or created when plastic breaks down). Their ingestion has been widely reported in marine organisms, including seabirds, fish, mussels, worms and zooplankton.
Oxo-degradable plastics can pose a threat to marine ecosystems even after fragmentation. It should be assumed that microplastics created in the fragmentation process remain in the ocean, where they can be ingested by marine organisms and facilitate the transport of harmful microbes, pathogens and algal species.
The report also cites research that suggested some people are attracted by technological solutions as an alternative to changing behavior. Labelling a product as biodegradable may be seen as a technical fix that removes responsibility from the individual, resulting in a reluctance to take action.