The world of “Green” (as in other industries) has its own terms and terminologies. For the person trying to make some sense of these and wishing to make positive environmental lifestyle changes it can get awfully confusing. Take for instance the terms degradable, biodegradable, and compostable when used in relation to plastics. There are major differences between the three and they will probably play a role in your purchasing decisions.
Degradable
Degradable plastics are oil based and break down through chemical reactions rather than the activity of micro-organisms and as a result they can degrade in an anaerobic environment into water, CO2, biomass and trace elements.
Most degradable plastics leave some form of residual particulates that are not environmentally friendly.
Biodegradable
Biodegradable plastics are made from vegetable starch in most cases and break down through the actions of naturally occurring microorganisms such as bacteria, fungi, algae, etc. over a period of time. The time period varies and depends on diverse factors.
There are many advantages to products being biodegradable, most of which are obvious. However, there are some disadvantages. When dumped in landfills, they are often dug under where the "good" bacteria can't survive in an oxygen depleted (anaerobic) environments. As a result, when they break down they create methane, a greenhouse gas.
Note: There are products which can fully biodegradable under anaerobic conditions without adverse effect to the environment.
Compostable
According to the American Society for Testing & Materials (ASTM), in order for plastics to be considered compostable, they must be able to break down into carbon dioxide, water and biomass at the same rate as paper. The resulting product also needs to look like compost, should not produce any toxic material, and should be able to support plant life. Compostable items are made from plant materials such as corn, potato, cellulose, soy and sugar.
The downside is that in order for these products to compost they need to be disposed of in composting facilities where strict environmental conditions are continuously maintained i.e. heat, moisture, etc. unfortunately, there are very few industrial capacity composting facilities in the US so it is likely your compostable plastics will just wind up in a landfill, which sort of defeats the purpose.
In Conclusion
Whether you choose any of the three types of plastics over standard plastic products you are benefiting the cause and demonstrating environmental responsibility. As with any emerging technology, biodegradable plastics will continue to improve and someday there may only be upsides to using the products. Until then, the choice is yours.
Portions of this article are courtesy of Green Living Tips. We encourage you to visit their site: www.greenlivingtips.com
