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Ask Umbra on corn plastic 19

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Q. Dear Umbra,

I’ve been noticing lately a lot of “green” businesses and restaurants in my area using compostable plastics, usually made of corn, if I recall correctly. I can’t compost (I know, I know, but I live in a tiny apartment on the third floor with no porch or yard), and I was wondering if you could tell us any more about this plastic. Should I recycle it, or throw it away? What to do?

Becky B.
Jamaica Plain, Mass.

A. Dearest Becky,

ear o cornCorn plastic = not fantastic.USDA.govDoes anyone find pictures of food appetizing? Right now I’m looking at a picture of some artistically arranged marinated olives in a bio-plastic deli container. I love olives. These are just repulsive. Perhaps the key to weight loss is photos of food.

I have a bit of scandale for you with these compostable plastic containers. The clear plastic #7 (which really just means “other”) cups and deli containers are made with PLA, which is usually a corn derivative but could also come from cane sugar. I was all ready to dork out on the science of PLA, polylactic acid, but then I read this: “Instead, lactic acid is oligomerized and then catalytically dimerized to make the cyclic lactide monomer.” The weather is too nice to spend time unraveling those polymers. Suffice to say they bacterially ferment the corn, then do all sorts of other stuff to stabilize it and turn it into a plastic. They can then make cups, fabrics, upholstery ... but who are “they”?

PLA is manufactured by agribiz giant Cargill at a plant in Blair, Nebraska. Cargill is a major player in the genetically modified corn market, is apparently the world’s largest grain handler, and operates its PLA product division under the name NatureWorks. The long and short of it is that this “green” plastic is made from GMO corn by one of the largest private companies in the United States, one with a terrible track record on environmental issues. Here is a useful overview of the Cargill-corn plastic connection that our own Tom Philpott penned a few years back. There are actual mini-scandals regarding Cargill and PLA, such as them trying to make a partnership with Patagonia for a PLA fleece. Somehow they neglected to mention the GMO corn behind the whole product.

So when we use these cups, we are supporting GMO crops and industrial ag. And we are not necessarily creating less waste; yes, the cups are biodegradable, but only in commercial composting facilities or other composts that reach 150 degrees with 90 percent humidity. So even if you composted in your apartment—which you could!—you likely would not have the right conditions. And there are problems with recycling corn plastic too—check with your friendly JP recyclers to see what they prefer. In the end, these cups can be equal to some products made from oil-based plastic: you just throw them out.

The only lifecycle assessment I could find was obviously pro-Cargill, so I can’t say how much petroleum it takes to make them. But I can say that products from conventional corn, a petroleum-intensive crop, are not the magic bullet. The magic bullet is to bring your own cup (on your bike, of course).

Polylactically,
Umbra

Yours is to wonder why, hers is to answer (or try). Send your green-living questions to Umbra.

Umbra Fisk is Grist Research Associate II, Hardcover and Periodicals Unit, floors 2B-4B.

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  1. mwilliman Posted 7:49 am
    12 Aug 2009

    Corn and other bio-based plastics are particularly tricky because to the casual observer, it looks like regular petroleum based plastics.  There is evidence that recycling as little as 1 part of PLA in 10,000 of PET (Petroleum based polyethylene terepthalate) will degrade the quality of PET and render it unusable as a recycled polymer.  This is a huge problem for recyclers and the source of great debate among bottlers and recyclers as some companies have started bottling their beverages in PLA bottles.  PLA bottles are NOT recyclable with PET (though they could be fed back into the PLA stream... Cargill does not have a collection system to recycle PLA so this point is moot) but they look just like it to the casual observer. Thus, unknowing recyclers can contaminate the PET bottle recycling stream by placing PLA bottles with their regular recyclables. NAPCOR (National Association of PET Container Resources) recently publicly refuted claims of recyclability of PLA.http://news.morningstar.com/newsnet/ViewNews.aspx?article=/BW/20090724005033_univ.xml I am no fan of petroleum based plastics either, but to tout bio-based plastics as being "green" is disingenuous and very confusing to people who are trying to employ environmentally preferable practices.  If you want a compostable cup use paper!

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  2. salubriousbaker Posted 9:55 am
    12 Aug 2009

    Dear Umbra ...you have made me very proud! not that i would expect any less, but, your answer to this question is spot on!thank you for being so well informed and for staying true to the reality of things! bravo!your very loving fanangela

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  3. SeaHorse Posted 1:38 pm
    12 Aug 2009

    In reference to the "bring your own cup": UnCommon Goods has a double walled (won't burn your hands, holds in the heat), ceramic (what is not to love?) travel cup (fits nicely in the car's cup holder) with a silicone lid (heat resistant, somewhat enviro material that doesn't absorb odor) sized to use the cardboard sleeve from your very last cup of CharBucks which is titled "I am not a paper cup".  I can't find one single fault with this travel mug/cup except it is small. 

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  4. llime Posted 4:50 pm
    12 Aug 2009

    Biodegradable has become a term that means : It must be good. But it isn't necessarily good at all.

    A biodegradable container that winds up at a landfill won't biodegrade for lack of oxygen and water. Even if biodegradation were to occur, it would produce gasses and liquids and support life. This isn't good at a landfill which ideally would be inert. 

    Roadside litter will slowly biodegrade. But those blobs of corn mush will become food for birds and rodents. Who knows what effect the non-corn ingredients will have on the animals.

    As previously noted, a container that looks like plastic can contaminate plastic that could otherwise be recycled.

    A very small percentage of biodegradable containers will be composted by individuals. And then they will have GMO corn and who knows what else in their compost.

    Containers are being produced that are more expensive, weaker, less reusable, not recyclable, less heat stable, and harder to dispose of than plastic. The advantage is that the containers suit people with the mistaken definition that biodegradable is always good.

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  5. MaxClark Posted 6:29 am
    13 Aug 2009

     I really appreciated your comments and have passed them on to everyone I know.  I agree, PLA isn’t a preferable alternative to current plastics.  PLA plastic is made from plant products but that doesn’t make it environmentally or consumer friendly.  PLA is made from genetically altered corn (here in the U.S) that isn’t fit for human consumption, will not biodegrade in a landfill environment, causes the increased use of pesticides which are causing an ecological disaster in the Mississippi delta region, reduces food grain supplies raising food prices, Reduces food grains that should be exported to countries that need our grain, and the only way to properly dispose of PLA is in a commercial composting site.  Try finding a commercial composting site near you.  Most PLA will end up in a landfill where it will languish for a long time.   Cards made from PLA are going to end up in the same place as current plastic cards…the landfill, and they won’t go away any faster than the stuff we now have.In my mind a plastic product should be designed so that it was biodegradable either an anaerobic or aerobic environment, which is the environment found in most landfills.    There are better alternatives which aren’t perfect, but better than the ecological disaster PLA is going to create.  There are plastics which have recently been developed which are biodegradable and will biodegrade in a landfill.  For example, the ENSO biodegradable plastic bottle with EcoPure is a plastic product that is designed to biodegrade in a landfill.  Other plastic products that are designed with EcoPure will also biodegrade in a landfill environment and they can be recycled.  Are they the perfect answer to our plastic problems?  No, but it is a step in the right direction.    Maxhttp;//www.ensobottles.com“Bottles for a healthier earth” 

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  6. Robert K Posted 3:06 pm
    13 Aug 2009

    I think the best solution for waste disposal is the plasma induction incinerators. The ultra high temperatures destroys dangerous chemicals and splits compounds into smaller molecules; and as a result energy is produced that can be turned into electricity.
    Many people don't remember the incinerator ship the "Vulcan" that the government used to destroy some of the stocks of binary nerve gases and other "dangerous materials". It was not hot enough to insure complete incineration. 

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  7. Robert K Posted 3:06 pm
    13 Aug 2009

    I think the best solution for waste disposal is the plasma induction incinerators. The ultra high temperatures destroys dangerous chemicals and splits compounds into smaller molecules; and as a result energy is produced that can be turned into electricity.
    Many people don't remember the incinerator ship the "Vulcan" that the government used to destroy some of the stocks of binary nerve gases and other "dangerous materials". It was not hot enough to insure complete incineration. 

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  8. llime Posted 3:52 pm
    13 Aug 2009

    Engineering plastic to biodegrade in a landfill is quixotic, dangerous, and pointless.
    Researchers have found that material such as newspaper does not biodegrade in a landfill. Designing a plastic to do so may be quixotic. That an enterprise is quixotic isn't necessarily a criticism but this enterprise is dangerous. Putting an additive in PET plastic that makes it a good substrate for anaerobic bacteria and putting the plastic in a landfill is creating a new ecosystem. This uncontrolled experiment of facilitating growth of bacteria in novel conditions with bacterial mutation in the presence of anti-biotics may not turn out well. Certainly the methane and CO2 greenhouse gases produced by biodegradation will not do us good. And there is no point to this. PET plastic shouldn't be put in a landfill. PET plastic can be recycled. A landfill is not a compost pile. It will not be converted to farm land. We are better off with landfills that are entirely inert. We should not be facilitating biodegradation in landfills. The equation that biodegrade equals good is a false equation.

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    1. MaxClark Posted 4:33 pm
      13 Aug 2009

      Alas, we've heard from a status quoer.  Yes plastic will biodegrade...in a landfill...and the biproducts are biogases and humus.  We believe that current landfill design needs to be changed.  We support bioreactor landfill designs.  Bioreactor landfills are designed to enhance biodegradation and capture those gases (LFG's).  Landfill gases are becoming a source of clean energy.  Recycling is good but with 150 billion  bottles being produced and less han 30% recycled...well, something needs to be done.  It's time to think out of the box and biodegradable plastics (not compostable plastics) are the answer.  Biodegradable plastics can provide a useful product, that can be recycled and when the plastic or product life is over it can be used to produce clean energy.Maxhttp://www.ensobottles.com

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  9. llime Posted 5:00 pm
    13 Aug 2009

    Alas, you have addressed none of my points. "Out of the box" ?  A decades old, useless phrase is not an indication of innovation.

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  10. mihan's avatar

    mihan Posted 2:30 pm
    14 Aug 2009

    Umbra, Interesting points, all... but you don't really answer the question, do you? What is one to do with the thing once it is in one's home?

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  11. MaxClark Posted 3:19 pm
    14 Aug 2009

    Bioplastics are not environmentally friendly.  It takes more energy to produce bio plastics then PET.  Once you get a biodegradable plastic home use it...reuse it...recycle it.  If it finds its way into a landfill it will biodegrade producing CO2, Methane, water, humus.  Methane can and is being captured to produce clean energy.  The microbes that "eat" biodegradable plastic can be found in a landfill anaerobic or aerobic environment.  Will microbes evolve into some new horrible human eating creature?  Who knows...it hasn't happened to William Rathje who wrote "Rubbish."  He has been doing archeology of garbage for decades and has yet to encounter the "creature."Max

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  12. PermieWriter's avatar

    PermieWriter Posted 5:39 pm
    14 Aug 2009

    On the infrequent occasion that I use corn utensils, I break them up some and put them in the municipal composting stream - at least in the two counties where I live and work. Most municipalities, at least in California, run very large, hot compost piles. I certainly haven't had any success composting the things at home. Too bad Whole Foods uses them so extensively.

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  13. oceansneedsharks Posted 2:16 am
    15 Aug 2009

    Dear Umbra,I'm still confused.What does "biodegradable" plastic (eg plastic bags) break down to?  Would it break down into smaller and smaller particles and somehow get into the foodchain?  Does it affect hormones?  Is it still plastic when it breaks down?  I regrettably have a couple of biodegradable plastic bags and don't know what to do with them?Should have avoided them in the first place, I know...Thank you. 

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  14. MaxClark Posted 6:12 am
    15 Aug 2009

    I wonder if I might ask a favor of you and your readers?  I'm conducting a short survey...takes about a minute to answer and doesn't ask for personal info...on biodegradable plastics.  Would you all please take a moment and answer the survey and if possible send it on to anyone you know that might be interested.  I want to get a fairly large sampling for my survey.http://www.surveymonkey.com/s.aspx?sm=1jP2phAEnzHznhDZrIWv_2fg_3d_3dThanks,Max

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    1. oceansneedsharks Posted 12:02 am
      16 Aug 2009

      Dear Max, I would have liked to answer your survery, but am not well-enough informed about "biodegradable" plastics to answer "yes/no" type questions or speculate about how long it would take to biodegrade.    I'm not very comfortable with plastics at all -- as far as I was aware, petroleum-based plastic never biodegrades, just breaks down into smaller and smaller pieces.  I hate having a plastic item that isn't recyclable and which I don't know what to do with or where it will end up.  My concerns with petroleum-based plastic are that it doesn't biodegrade (as far as I know) and that it is clogging up the oceans and other ecosystems and killing wildlife.  I've also heard that tiny pieces of plastic can get into the systems of creatures, affecting hormones and development.  I'm worried about "biodegradable" plastic if it's "fake" biodegradable and causes pollution and problems in some other ways.    I guess if petroleum-based plastic can be recycled, that is somewhat better than it ending up in the planet's ecosystems.  

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  15. Matt Petryni Posted 12:20 am
    16 Aug 2009

    Umbra's right. Also, the plastic made from corn proves to be a relatively tricky bugger - sometimes they will not break down at all. I find myself removing them from my composting operation just as I would an errant grocery bag or any other instance of oil-plastic.Throw on the whole GMO corn issue and we're right back where we started. Many of the zero-waste merchant trailblazers who initially picked up "biodegradable" plastic foodware are now switching to back to wood and paper. Or encouraging re-use, of course. In a couple years, the pseudo-biodegradable, heavily-processed, GMO corn plastic will likely fall by the wayside. It was a good try, though. We can't get em all right, god knows.Thanks again for the interesting post Umbra!

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  16. Steve Davies Posted 10:59 am
    24 Aug 2009

    I manage sustainability programs for NatureWorks, which produces  Ingeo, the polylactide (PLA) in discussion.  We appreciate the interest and strong opinions that bio-plastics generate, given the growing passion and recognition of the thorny issues facing us as society – whether it be global warming, oil dependency and geopolitical instability, or the need for waste reduction through recycling and composting.  Today’s environmental problems call for some major innovation in our thinking and our products.   As Umbra has described, NatureWorks makes Ingeo using plant sugars – we ferment dextrose to make on a commercial scale, lactic acid, something that is found in nature, and the starting point for Ingeo.We started our business with the firm belief that “that the perfect should not be the enemy of the improved.”  Of course our products still leave an environmental footprint, but our goal is make it much smaller than the footprint it’s replacing. Nearly all plastics and performance fibers until now have come from oil - something that’s bad for our environment, and bad for our economy.  We’ve shown that you can create such  products from a renewable source, with a lower environmental impact, and with some new options after their use. We don’t pretend that all the questions are answered.  We’re tackling some pretty sizeable challenges that face us as a civilization, and are not naïve in thinking that there’s going to be a ‘silver bullet’.  At the same time, we’re proud of the progress we’re making, whether that be on the source of the sugar we’re using, how we address concerns over the agricultural growing practice behind those plant sugars, the carbon footprint of the Ingeo we produce, or where the materials can go after their use.  In short…Today, these sugars are derived from field corn that is already grown for many industrial and consumer end-uses. Ingeo uses less than 1/20th of 1% (0.05%) of the annual global corn crop. Ingeo doesn’t require corn, it only needs plant sugars. The future for Ingeo is that it will be made from cellulosic raw material — agricultural wastes and non-food plants.  The manufacture of Ingeo does not require genetically modified (GM) materials.  Ingeo is made from plant based sugars as its source and is certified by independent lab Genescan to contain no genetic material of any kind. However current US corn grown produces a mixed stream of GM and conventional corn. For those around the world for whom this is an issue, NatureWorks sources certified GM free corn.  There’s an incrementally higher cost for this from the farmer, and our customers for whom this is a concern support that with their purchase. NatureWorks has had independently peer reviewed and published, a comprehensive eco profile of Ingeo which defines the impact of our product, from field to factory gate, across 9 different metrics. http://delivery.sheridan.com/index.php?ID=GEN_114998_EP).   We’re better on many parameters than the oil based materials our customers seek to replace, not so good yet on others.  Key to most customers is the green house gas and energy profile of the polymers as they’re produced.  The manufacture of conventional polymers for example produces from 2 to 8 times their own weight in CO2, dependent on the polymer type (a hidden carbon footprint behind those products we all as consumers so take for granted).  As compared with PET for instance,  each pound of Ingeo resin releases about 60% less greenhouse gas emissions and consumes about 50% less non-renewable energy. That’s significant no matter where product ends up after use, and in parallel, we’re working hard to ensure that ingeo doesn’t suffer the same landfill fate of the vast majority of the existing plastics today...  Many of you want to understand composting options better, and this is one of the things that really excite us about this technology.    Unfortunately today, a tremendous amount of food waste is condemned to landfill – unable to be treated in composting systems even where they’re available, because that food waste is contaminated with oil based cutlery, plates, cups, etc (no-one is willing to separate the food waste from those utensils).   The use of compostable foodservice ware offers the potential for food waste diversion from landfill (something now legislated in some regions such as the EU) – in other words, allowing it to all be simply composted together.   Of course we’re not the only option here; other materials satisfying the ASTM6400 composting standard offer the same potential.  Equally, for brands or retailers to pitch ‘compostability’ where such an end of life is irrelevant to the consumer is wrong, and we work hard to prevent that happening too. What we’re doing on each of these fronts is - obviously, a lot to cover in a post, and I’d invite all interested to check out where we are in our journey on all of these fronts (http://www.natureworksllc.com/~/media/News and Events/NatureWorks_TheIngeoJourney_pdf.ashx).  To say current with as we progress on this journey visit our website.  www.natureworksllc.com.  Steve DaviesNatureWorks. 

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  17. MaxClark Posted 5:34 pm
    24 Aug 2009

    Check out thei information regarding genetically modified corn.  PLA uses genetically modified corn.You can read the whole article on natural news.com.  It is some interesting information on GM products.(NaturalNews) PepsiCo's 2009 shareholder proxy report contains a proposal (pg. 61) that paints a clear picture of the company's use of genetically-engineered (GE) food ingredients and its attitude toward this issue. The proposal describes a loose plan to remove GE ingredients from Pepsi's products in order to maintain "Company product integrity." The concern, archived for public record in the report, is that Pepsi products contain "potentially GE" corn, rice, canola, soy and sugar.

    The controversy of GE cropsis not a new one. For years, proponents of the biotech industry have maintained that GE crops are completely safe for human consumption and will benefit the world, while campaigners against GE foods have contended that the long-term dangers of this branch of science are unknown and uncontrolled. We now know that GE crops can pose extreme dangers for human consumption, animal consumption and for the biodiversity of the environment.

    The report cites twelve well-documented incidences or studies in which the dangers of GE crops are clearly demonstrated. The evidence includes a 2007 study conducted in Paris, France, where rats were fed GE cornmade by US biotech giant Monsanto. The results, which were published in the journal Archives of Environmental Contamination and Toxicology, were very unfavorable for the corn. The rats showed "signs of toxicity" in the kidneys and liver and developed problems in those organs.I don't think I want PLA wrapped around my food or holding my food.  Maybe I'm over reacting, only time will tell. Max

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