Picture from Worldcentric
There is some confusion regarding the labeling of biodegradable vs. compostable, specifically in plastic products and containers. This confusion is misleading customers into believing that biodegradable is a positive and reliable measure where the purchase will have little impact on the planet compared to standard plastics that are landfilled or recycled. I’m going to focus on disposable tableware commonly used for take-out and home entertaining.
Definition of compostable plastic:
To be compostable three criteria must be met.
1. The plastic needs to breakdown into viable soil enhancers and leaves no toxic residue. This means the product breaks down into carbon dioxide, water and biomass at the same rate as paper or cellulose.
2. At final disintegration there is no visible materials that need to be screened out.
3. The biodegredation does not produce any toxic material or residue and can support plant growth.
What is “plastic corn”
Compostable “plastic” is PLA, Polylactic acid.
Normally made from corn grown in the USA.
The leading corn plastic company that makes plastic containers and cups is NatureWorks , a joint venture of Cargill and Teijin.
Compostable plastic complies with ASTM standards ASTM-D6400 and European EN13432
Definition of biodegradable plastic:
Biodegradable plastic is plastic that will degrade from natural microorganism, such as bacteria, fungi ect. The difference from compostable plastic is that there is no requirement that there is no toxic residue and no time frame for how long the plastic degrades. Most of biodegradable plastics are meant to decompose in a landfill and not in a compost facility. ASTM D5988-96
Definition of degradable plastic:
Plastic that undergoes a significant change in chemical structure under specific environmental conditions resulting in a loss of some properties.
No requirement that the plastic has to degrade from the action of naturally occurring microorganism or any other criteria required for compostable plastics.
An example of this type of plastic can be found on: biodegradable plastic
The European union was dissatisfied with the confusion the label of biodegradability created for consumers and determined that biodegradable would not be an acceptable label. At present they endorse the labeling of compostable or landfill products only to minimize confusion and keep companies transparent.
In the European Union products the standard of “Precautionary Principle” dominates labeling and code standards. This policy will be discussed in detail in another blog.
The European precautionary principle (PP) standard and labeling policies are under constant pressure and criticism by the plastics industry and we will keep monitoring their progress.
Personally, I like the PP. It’s clean, neat, simplified and puts the pressure on companies to prove their products and practices will do no harm to the environment, people and reduce the risk of future problems in the light of insufficient scientific data. This reduces the probability of problems such as lead in childrens toys, toxins in food and everything we here in North America need to litigate personally or as a class action suits to repair damages done to us and the taxes we pay for environmental clean-up.
In the meantime, as zero waste practitioners, the best way to prevent and eliminate these issues is to not use disposable products of any kind. Use ceramic plates, metal cutlery, glass cups and cloth napkins for our own events at home or away. Slow down and to eat on proper plates and cups in the restaurant or café we buy the food in instead of eating on the run or in the car is extremely effective to become the zero hero we strive to be.