Biodegradable Polymers and Compostable Plastic
The average American produces 4.5 pounds of waste per day (http://www.eia.doe.gov/kids/energyfacts/saving/recycling/solidwaste/primer.html). 9 to 12 percent (by compacted volume) of the waste in landfills is plastic (http://www.enviroliteracy.org/article.php/1268.html). Plastic is easy to produce for a huge variety of applications, is not affected by the elements and does not degrade easily. Unfortunately, the ease at which plastic is produced is at the cost of using unrenewable fossil fuels. The stability of the product and the fact that plastic is biologically inert is a beneficial property during use. After use, it is only detrimental to the environment by creating a huge amount of waste that cannot be broken down. Plastic that escapes landfills or is simply dumped into the world’s oceans has a huge effect on wildlife, usually by suffocation.
Biodegradable plastics serve as an excellent alternative to most traditional plastic products. Biodegradable products have many of the pros of traditional plastics (durability and ease of production) without all of the cons. Biodegradable products are produced from renewable plant resources. Often, they are even produced from plant waste products such as the husks of corn. The major input is plant materials and the only output is compost. Biodegradable products are easy to produce and provide a durability similar to that of most plastics. The greatest benefit of biodegradable plastic is its ability to be broken down by biological processes.
In 2000 the US Composting Council and the Biodegradable Products Institute created a certification program based on the ASTM Standard D 6400-99 which defines three different levels of degradable plastic:
- Compostable plastic: Plastic that breaks down in a manner and time period similar to other compostable materials such as food waste and yard clippings. The plastic must disintegrate completely into CO2, water and inorganic compounds while leaving no visible toxic residues.
- Biodegradable: Plastic which can be broken down by natural processes including bacteria, fungi or algae. This plastic does not have to break down in a certain time period and may leave toxic residues.
- Degradable plastic: Plastic that undergoes some change in properties in a certain amount of time. The change in properties could be a change in shape or strength but does not specify breaking down to a certain size, time frame, or toxic remnants left behind.
The consumer should check for certification on each product that they buy. Compostable plastics break down with ease and do not require any additions to traditional composting methods. They can be added to compost pick up bins or composted at home on a small scale. Compostable plastics have been most effective at replacing traditional plastics for single use products such as cutlery and bags. For these products, the durability is not as vital and compostability is a huge benefit. When compostable cutlery is used, all waste can be composted without the need to sort and separate compostable food waste from uncompostable plastic waste. At the 2000 Olympic Games in Sydney, all food was served on compostable plateware with compostable cutlery. This led to 76 percent of the solid waste produced at the games being reclaimed ().
At the same time, compostable plastics will not break down as they should if they are placed into a landfill. A landfill is not conducive to life and most microorganisms that would break down the plastic cannot survive there. A system should be put in place to inform the consumer that the plastic they are using is compostable and must be disposed of in a different manner than most plastic.
“The U.S. Environmental Protection Agency estimates that if the United States collected and composted the 21 million tons of food scraps generated annually instead of sending them to a landfill, it would have the same global warming benefits as taking 2 million cars off the road” (http://www.astm.org/SNEWS/APRIL_2001/mojo_apr01.html). While on the boat with Beam Reach, we do an excellent job at collecting compostable waste. Beam Reach produces an average of 2.03 kg of waste each day. 30.8 percent of that waste is recycled, 27.8 is composted and 41.4 goes to a landfill. Some of that waste is plastic bags and packaging. If that waste were compostable, instead of being traditional plastic, less hydrocarbons would be obtained from fossil fuels to make plastic. Less waste would be taking up the unrenewable resource of space and we would emit less greenhouse gases into the atmosphere. We would be able to compost more of our waste to replace the energy and soil mass depleted from the environment during farming. Beam Reach could take the steps to purchase and use compostable plastic bags for garbage and visits to the farmers market and grocery store. For bags that could be reused many times, cloth bags would be an appropriate investment for the program.
In the future, if compostable plastic packaging becomes more prevalent, Beam Reach could be conscious of the products it purchases. By making a point to purchase products packaged in compostable plastic, Beam Reach would encourage and provide incentive for more companies to use compostable plastic in packaging.
Plastics are a huge part of our lives and while we cannot eliminate the use of traditional plastics, we can reduce it. By using compostable plastic for single use products such as packaging, cutlery and bags we can reduce our use of fossil fuels and reduce the amount of waste choking the environment.
For more information on compostable and biodegradable plastic products: http://www.google.com/search?hl=en&q=compostable+plastics