How to compost plastics, even biodegradable plastics can be a continuing quandary.
Petroleum Based Plastic
Many plastics are created from petroleum based products which make them non-biodegradable. However, if you take the time to find and use plastics that are made from biodegradable materials then you can simply add them to your composting pile or pail.
This, however, is trickier than it might seem.
There are a number of products that are attempting to reach the green-conscious consumer by marketing their plastic products as biodegradable. Unfortunately, this name may not mean much when it comes to telling you if a product is able to be put into a landfill.
There is no regulation when it comes to the term “biodegradable.” No one has a specific definition of what that term means, so products that carry this name break down at very different rates, which vary in different environments.
The current best method of determining the ease with which a biodegradable product will break down (and therefore be useful in your home compost pile) is to use the American Society for Testing and Materials standards (ASTM standards) for determining how well the products will break down in different environments. If not shown on the label, a consumer would have to call the cup manufacturer and ask for the study results.
Home Compost Pile
Even the most biodegradable of plastics, such as those made of sugar cane or cornstarch, may not be appropriate for a home compost pile.
ASTM standards are sat for biologically active landfills, where moisture is present and microbes are allowed to grow. These conditions may not exist in your own compost pile, with limited materials and a motivation on your part to limit unpleasant smells that would bother the neighbors.
Choose the Best Available
The best you can do is choose plastic materials that have the circular logo sporting a tree and a leaf that is applied to biodegradable products by the Biodegradable Products Institute and the U.S. Composting Council.
These products are guaranteed to decompose in a professionally run composting facility, and may work in your backyard compost heap.
Before putting these plastics in the compost bin, however, you will need to shred each piece of plastic into small pieces, which can be a tedious task.
Better Solutions Are Coming
This area of technology is improving rapidly. Advances are being made currently in corn based plastic packaging that will break down in a matter of months under the right conditions, for example.
As this technology continues to improve, there will be more products that are more easily composted in your own backyard compost heap.