Compostable plastics offer several benefits, along with some limitations.

Compostable Plastic

World Centric® compostable plastics are made from Ingeo™, a bio-based plastic derived from renewable corn in the U.S. Chemically, this material is known as PLA, or Poly Lactic Acid, which can be derived from a variety of plant-based starches.

Benefits 

Limitations

Discussion Compostable plastics are a new generation of plastics. Generally, they are derived from renewable plant-based materials like starch, cellulose, and soy protein. However, the field of compostable plastics is constantly evolving, with new materials and technologies in development. For example, compostable plastic resins can be derived from petroleum, as well as from carbon dioxide and methane. New hybrid plastics composed of both petroleum-based and plant-based resins are also coming to the market. These may confuse consumers who want to make the most environmentally responsible purchases they can. Bio-based, nontoxic, compostable plastics are the best choice for disposable foodservice products that will be contaminated with food waste when they are discarded and cannot be recycled easily. Compostable plastics can fully re-enter the cycle of life by becoming fertilizer for new plants.

One of the most popular plant-based resins for consumer products is Ingeo (technically known as polylactic acid or PLA). Ingeo has a heat resistance of 110°F and is well suited for clear cups, deli containers, straws, etc. It is made from dextrose, a sugar produced by plants. Currently, the most common raw material for Ingeo is field corn, although other plant sources may be used in the future. Ingeo production uses only 1/20th of 1% (0.05%) of the global supply of corn stock, so the impact of Ingeo production on global corn prices is miniscule.2 On average, the production of PLA plastic resin consumes about 50% less energy as the production of petroleum-based resins (53% as compared to PET, 59% to PP, and 48% to PS). Similarly, the production of PLA plastic resin emits about 60% as much CO2 as the production of petroleum-based resins (45% as compared to PET, 77% to PP, and 53% to PS). 3, 4

Besides Ingeo, other bio-plastics are commercially available as well, made from plant-based resins derived from potato starch, soybean protein, and cellulose. Increasingly, instead of choosing petroleum-based plastics that create toxicity and environmental pollution, consumers can choose products made from compostable, renewable bio-plastics.

Page Notes:

  1. NEED SOURCE for composting times.
  2. From Plants to Plastics; Nature Works; http://www.natureworksllc.com/the-ingeo-journey.aspx; Retrieved March 15, 2012.
  3. Eco-profiles for Current and Near-future NatureWorks Polylactide (PLA) Production, Vink Ervin, NatureWorks, http://delivery.sheridan.com/index.php?ID=GEN_114998_EP-, 1 November 2007.
  4. What’s Your Process Energy Fingerprint? Robin Kent, Plastics Technology, http://www.ptonline.com/articles/whats-your-process-energy-fingerprint, March 2009.

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