Sunday, April 11, 2010

Biodegradable vs. Compostable plastic labeling

 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.


  1. i like clean trash...

  2. Good information. Good luck on eliminating plastic altogether. Go in to any store, look at any row and you will see plastic of some sort. I don't think we're going to see plastic going away anytime soon. The fact is that the carbon footprint of plastic is better than aluminum and glass. The problem with plastic is that it doesn't go away, at least not very fast. That's why we got involved in developing a biodegradable plastic bottle. Our bottle, the ENSO biodegradable bottle, is designed to biodegrade in the anaerobic environment of a landfill. We know that 70 percent of plastic bottles will end up in a landfill and we thought a realistic approach would be to do something about all the plastic headed for a landfill. When our bottle biodegrades it produces landfill gases (methane) which can be captured and used to produce clean energy. Our bottle is not the final answer; we continue to do research to find that answer. In the meantime, the ENSO biodegradable bottle is the best environmental solution on the market.
    "Bottles for a Healthier Earth"

  3. Plastic is a tough one to eliminate. Here in Michigan we have a great bottle return rate due to the increased bottle deposit, so that helps bring them back into the loop but recycling is not the issue here. The problem is the labeling of biodegradable vs. compostable and the confusion it makes.

    When we hold a zero waste festival and event we want as little as possible to go to the landfill, some to recycling and most of it to be composted, if not washed and reused.

    Confusion has occurred between the planners and product sales reps who say their product is the right fit for their function when it will actually be sent to a landfill as biodegradable and rejected by the composter.

    Cleaner, clearer labeling such as the EU imposes eliminates any such confusion.

    There is enough to do when planning a function than to have to read the specs on every piece of disposable product you are bringing in to be sure it is actually a compostable item.

    Any event (indoor or out festivals, concerts, market stands, bakeries, cup of coffee) I attended in Germany had real cups, beer glasses, plates and cutlery removing the need for any of these debates and I would prefer it to be so here as well, but understand disposable is a way of life here, so if we want to make it as low impact as possible clear unconfused labeling of product will help.