What are the benefits of corn based plastic? | AzSustainability.com

What are the benefits of corn based plastic?

Corn Plastic Cups

Photo by: Majiscup

Corn plastic or PLA (polylactic acid) cups, utensils, and packaging have been popping up everywhere and I have been curious how they stack up against conventional plastic. It seems obvious that plastic made from corn would be more eco-friendly right? I did a little research and compiled a list of PLAs green pros and cons.

Pros:

  • Manufactured from corn starch, a renewable resource.
  • Biodegradable, breaks down into mostly carbon dioxide and water.
  • Compostable, 6-12 months in a home composter (Many people are reporting that they will not compost in a home composter), 1-6 months in a commercial composter. Longer for heat resistant utensils. Once composted it is indistinguishable from the other compost.
  • Does not emit toxic fumes if incinerated.
  • Does not leech chemicals into food or soil.
  • Freezer safe.
  • Can handle hot items up to 120F (200F for utensils).
  • Looks, feels, handles just like plastic.
  • Is inexpensive.

Cons:

  • Is not recyclable, must be kept separate from plastic.
  • Few commercial composting facilities (113 in U.S.), only 1/4 of which accept residential materials.
  • Commercial Composters use Microbes to break down organic material. Large amounts of PLA in a composter would cause problems because it breaks down into lactic acid which is wetter and more acidic. They can break this down but it requires more oxygen for the microbes to consume. Commercial Facilities would have trouble providing enough oxygen for large amounts of PLA to breakdown. Anaerobic digesters would not have the same problem.
  • It is estimated that in a landfill PLA will take anywhere from 100 to a 1000 years to biodegrade.
  • Typically made from genetically modified corn and usually not organic.
  • Diverting corn away from the world’s food supply.

To me the cons don’t seem too bad considering plastic can’t be composted, takes longer to decompose in a landfill (starts decomposing after around 700 years), and can leech chemicals into food and the soil. Overall I think PLA is a pretty good substitute for disposable plastic cups, utensils, and packaging.  What do you think? Any more pros and cons?

edit: Lots of good comments made and a few saying that perhaps these are not as eco-friendly as their manufactures want you think. See comments for details..

For more in depth information check out these links:

17 Responses

  1. Ali Syme Says:

    Thanks James!

    Another pro is that corn based plastics use less energy in production than regular plastics - so machines don’t use as much energy making corn based goods as regular plastic goods.

    Ali

  2. Tracy Says:

    Great info! Thanks for the post, I’ve been wondering about this. Sometimes it is tough to weigh out these kinds of decisions and it brings up the biofuels food supply type controversy but ultimately it seems better for the planet. Now if we could all just compost and stop entombing our trash in landfills we’d be a lot better off.

  3. Clintus Says:

    My work just started using these. I like it.

  4. Columbine Says:

    I’d be curious to know which kind of plastic uses more water in its manufacture.

  5. Tracy Perkins Says:

    … still thinking about this post :c) I wonder how they measure up to containers made from potato starch instead of corn. http://www.potatoplates.com/

  6. web design company Says:

    all the pro s and con s you ever wanted to know about PLA (corn based plastic). great post!

  7. Leslie Says:

    Please wake up America!! It states on the NatureWorks website that they buy energy creditd in order for their PLA to be sustainable. PLA uses MORE fossil fuels than regular plastics!! Containers only degrade in commercial composts (as noted) but only 28 exist in the US. They will NOT degrade in backyard composts.The World Food Bank states that 75% of the food shortages today are a result of corn grown for nonfood products- PLA and ethanol. The excessive nitrogen used for growing the corn has created a dead zone in the Gulf of Mexico the size of New Jersey! GMO’s are killing monarch butterflies and other friendly insects.PLA is the worst product to use!!

  8. john Says:

    Great!…

    but why not use a glas or cup, which you can wash and use countless times?….

  9. James Towner Says:

    I’d definitely say reusable is the way to go. Not sure why more cafes don’t offer a mug or glass? Obviously some people want to go stuff, but many also just want to sit down and enjoy their drink there.

  10. Paul Smith Says:

    Thanks so much for the thorough breakdown here. I don’t have an answer/alternative on these, however I have recently come across and become a huge fan of Verterra plates. They’re made from fallen palm leaves, that would otherwise likely be burnt as agricultural waste. That’s it.

    Somehow they’re super tough, and I’ve been able to wash and reuse them multiple times. And I hear you can even bake with them. As far composting, they say they take 3 months in a home composting system. An eco slam dunk here, I’d say.

    Here’s a recent article I saw on them http://www.reallynatural.com/archives/product-review/biodegradable_verterra_dinnerw.php and their site http://www.verterra.com

  11. Paul Smith Says:

    Other things to consider with corn based or any food based plastic is, what is the source? Is it GMO? Or organic? Where is it grown? How far does it ship to get to me?

  12. Adam Says:

    80 percent of the corn grown in the U.S. is not for food consumption already. It’s either for H.F.C.S. or E85 or Cattle Feed. We shouldn’t be using it for any of those things anyway.

    Corn Plastic is so wrong, but then the all the Farmers would need is another G.M.O. Seed from Monsanto to boost yield and ruin the environment some more!

  13. Val Says:

    I recently bought several corn based water bottles w/ filters believing that at least we would be making more of an effort to reduce the amount of plastic. I was not aware that they were not recyclable along with other plastics. When at all possible, we do use glass mugs, etc. but it is not always feasable. For years, I/we have recycled the plastic water bottles over & over only to find out that they contain toxins…not sure which is the worse of 2 evils…Both my husband & myself were diagnosed with cancer this past year - my husband w/ Hogdkins & me w/ breast cancer. I wonder if there is anything that doesn’t affect your health & benefits the environment at the same time?

  14. Bryant Says:

    You need to recheck your facts about PLA and composting. Natures Work (producer of PLA) is very specific about PLA only biodegradable in a commercial compost setting not backyard compost piles. It needs the high temperatures generated in the commercial facility.

    PLA’s heat instability is also a factor that must be considered. For example, shipping PLA packaging during the summer in tractor trailors exposes the product to temeratures exceeding the 120 degree level causing distortion. Using climate controlled trailors reduces the units that can be transported in the trailor thus increasing the fuel required and emissions generated.

    Your last point can be taken a step further and none of the proponents add this to their calculations on net greenhouse gases. Given world demand for grains and mandates for ethanol use in fuels, any increase in the demand for corn will create a need to expand farm acreage which will result in the loss a carbon sequestration by establish plant growth. The ethanol proponents never include this calculation in their facts, either.

  15. Paula Says:

    Nice try. But a plastic is a plastic. What we need is to go BACK to the containers and transport systems used in the ’50’s. People re-used their containers which were made of glass or pottery. If something is not biodegradable in the family compost pile, America needs to be told THE TRUTH up front. We’re grasping at straws here. True innovation comes from God. He is the creator and author of all things.

  16. Becky Says:

    GREAT!!!!!! This information is very useful

  17. Richard Says:

    Reply to Paul Smith, who is working for Verterra:

    Critique of Michael Dwork, founder of Verterra

    I am an occasional reader of Time magazine and stumbled upon a business article by Jeremy Caplan on Verterra Dinnerware in the October 13, 2008 edition (Australian) of Time (page 52). Also at: http://www.time.com/time/specials/2007/article/0,28804,1706699_1707550_1846340,00.html

    Jeremy Caplan’s article is careful not to over-state or claim. However, it strongly implies that Michael Dwork had an “idea” in southern India in 2006, that Mr Dwork developed his idea with “engineer friends”, “crossed Asia to find plants for his plates”, “through Laos, Thailand and Cambodia”, “testing dozens”, “in search of the perfect leaf” and so on. Before settling on a palm leaf in southern India - wow.

    I think it should be known that plates and bowls steam-pressed from the leaf-base (sheath) of the Areca (the so called ‘betel nut’) palm (Areca catechu) have been manufactured in southern India since long before 2006.

    Indeed, in 2006, steam-pressed Areca palm plates and bowls were already in Indian city stores and on display at trade expos in southern India, and have been imported into Australia with the name of Eco-Vision Bioplate since 2005 or earlier. Areca plates have also been imported into Germany, Switzerland and United Kingdom since or before 2003.

    Jeremy Caplan’s article includes a photo of Mr Dwork leaning on a small palm tree. I can say, with reasonable certainty, that this small palm is of the species Areca catechu, the common, plantation, Areca palm.

    It seems Mr Dwork copied a well established product (material and method) and imported Areca plates into the US market - which is hardly an “entrepreneurial gamble” and is definitely not an original idea.

    Mr Dwork was a member of the ‘entrepreneurship class’ at Columbia School of Business. Mr Dwork went on, with ‘his idea’, to become the 2007 winner of the A. Lorne Weil Outrageous Business Plan Competition, and received $100,000 in seed funding from the Eugene M. Lang Entrepreneurial Initiative Fund - which is remarkable considering the Lang Fund’s emphasis for originality.

    What is outrageous is Michael Dwork appearing to grab the credit and failing to acknowledge Indian ingenuity, Indian producers and Indian exporters who have manufactured quality steam-pressed Areca plates identical to the Verterra product, and who have done so for years before Michael Dwork arrived in 2006.

    For a history of the Areca plate visit:
    http://www.ecovision.com.au
    http://www.eco-vision.in/companyprofile.htm

    This limited critique has been sent to the following:
    Michael Dwork michael@verterra.com
    Jeremy Caplan via Time
    Time magazine
    Columbia School of Business
    United States Patent and Trademark Office
    The New York Times
    New York Post
    And others.

    Richard - Murwillumbah, Australia.

    30th October 2008.

    Critique of Michael Dwork and Verterra - continuation.

    The overdeveloped salesmanship practiced by Michael Dwork and Verterra includes the assertion that shipping palm leaf sheaths from India to New York is okay because rural people would otherwise only burn the sheaths. This claim by Verterra is deceptive.
    Although palm leaves may sometimes be burnt for mosquito control, it is arrogant for Mr Dwork to infer that Indian farmers are not aware of the benefits of putting organic material into the soil (composting/mulch).
    Also, in rural India cooking is usually over a fire, and dried palm sheaths are an excellent fuel for the domestic fireplace. Removing Areca palm sheaths from rural areas may have unforeseen impacts, as other sources of cooking fuel need to be collected from the forest or fields.

    Verterra are proud to own extensive production facilities in India, which is, no doubt, the optimum for New York based Verterra’s balance sheet.

    Although Verterra’s facilities provide employment, its wider value for rural development is questionable, and may even be detrimental for rural self-esteem, as the villager labours for the foreign company that stole ‘their’ product.
    Other producers of Areca plates include village cooperatives, the greater benefit for rural development would be obvious.
    If your concern is to support rural development in India, please consider Areca products from village manufacture.

    I like to have Areca palm containers for display in the home. However, from the environmental perspective, the promotion of any single-use dishware is not appropriate - unless intended for areas with serious water shortages.

    In Australia, artists make delightful baskets and ‘sculpture’ from the leaf sheaths of the Bangalow palm Archontophoenix cunninghamiana, which is also an Arecaceae Palmae.

    Richard - Murwillumbah, Australia.

    Yes, I am a frequent visitor to India, and I do not have any financial interest in any business associated with Areca products.

    14th November 2008.

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