Corn Plastic as Green as Advertised?
It seems that everything we buy is either made of plastic or packaged using plastic. Since plastic is traditionally made from petroleum, it’s extremely harmful for the environment. Some companies are beginning to use a new type of plastic made from corn with claims of being biodegradable and more eco friendly to produce. But, is this new type of plastic really so green as manufacturers are advertising?
How It’s Made
Petroleum based plastics are made from a polymer material that is formed as a by product of refining crude oil and natural gas. The process to get this polymer produced and to turn it into plastic produces large amounts of greenhouse gases and needs approximately 200,000 barrels of oil a day.
A resin known as polylactic acid (PLA) is the base of this new type of plastic that is made only using corn. The kernels are milled and dextrose is extracted from the milled corn. The dextrose is then allowed to ferment, producing lactic acid as a by product. The base of PLA is formed by linking polymers of lactic to create pellets similar to those that are created from petroleum refining.
Benefits
Environmental
PLA is a far more environmentally friendly plastic that the petroleum counterpart. Producing it generates 68% less greenhouse gases and has no toxins since it’s made from corn. One of the biggest marketing points for PLA is that it is completely biodegradable. They are claiming that it will break down into carbon dioxode and water in just 90 days. Though a controlled composting environment is required, it’s exciting to think that plastic could be far less dangerous on the environment that it already is.
Cost
The price of PLA has gone dramatically down since it was created. Just 20 years ago it costs over $200 a pound to make and now costs under a dollar. The main reason for this low cost is that low-grade corn is used produce it. This means that corn is not being taken away from food supplies. With so many people hungry in the world, taking additional food supplies for non-food use would be horrible. With the influx in oil prices over the last few years, PLA could very well be cheaper in the near future. At the moment, larger companies are able to get a comparable price to petroleum based plastics, while retailers are still paying more for it. It could get really interesting if the price of PlA becomes less than PET.
Non-Leaching?
I can’t say for certain that this is truly a benefit as I could not find a definitive answer as to whether or not PLA has leaching properties like certain types of petroleum bases plastic. There are several references as to the fact that it is non-toxic and does not not leach though. If true, this would make PLA far safer for human use and the environment once disposed of.
Drawbacks
Since PLA seems to solve some of the issues that traditional plastic has, why hasn’t it already taken control of the plastic market yet?
Less Versatile
PLA is just not that versatile like traditional plastic. The biggest issue with it is that it can’t go above 114° without melting. This is the main reason you will never see PLA completely take over for traditional plastics like plastic polyethylene terephthalate (PET). Forget making plastic grocery bags or using it for hot foods.
Not Compostable?
After just saying that PLA is biodegradable as a benefit above, I am now saying it’s not? Well, it is technically biodegradable, but as I said above under controlled conditions to speed up the process. There are only 113 facilities nationwide that are able reproduce this controlled compositing environment. If you were to start your own compost and put PLA in it, it just wouldnt’ compost as quickly. Even large composters aren’t prepared to handle large amounts of PLA.
Microbes will consume the lactic acid, but they demand a lot of oxygen, and we’re having trouble providing enough
The biggest concern is that if it does end up in landfills, will it actually break down any faster than traditional plastics?
Hard to Recycle
PLA is actually a problem for recycling facilities as it does not mix well with PET plastic. Recycling plants actually consider it as a contaminant and have to pay to have it sorted out. Some PLA producers are saying that they are willing to buy their product from recycling facilities so that they can properly recycle the material or allow it to compost.
The Verdict
Corn Plastic has come on strong and even being used by some large companies including Newman’s, Wild Oats and even Walmart. It’s uses are limited, but it could really make a huge difference by eliminating tons of greenhouse gases and reducing our dependency on oil. There are also some issues with how biodegradable it really is, but I think this new type of plastic is change from PET plastics.
A big concern by some is that corn plastics are just feeding to our unnecessary over packaging of our products. Even though it is considered to be a “green” product, is it really green that we are justifying our over-packing by lessening it’s impact on the environment. It’s still a move in the right direction and hopefully it will make a difference.
Comments
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January 26th, 2009Trackback from : Recommended Reads « Easy Going Green
It sounds like a start but as you say it is all about cutting down on our overpackaged lifestyle.
Thanks for the great info! I’m glad we are trying to make a positive move.
Erm, PLA does not cost less than conventional plastic. What are you looking at for this info? Methinks it is not raw material prices.
You are very correct that the cost is not less than petroleum based plastics. I misread something in an article I was reading about it. I made the correction to that section. Be sure to contact me if you find any further mistakes.
I commend innovation and the introduction of plastics that will help with the plastic problem. Plastic bottles are a growing problem in our landfills and oceans. We felt that something needed to be done……and now.
We felt that plastics made from crops that could be producing food, wasn’t the answer. In fact we were wondering what would become of all the PLA plastics produced. PLA plastics won’t biodegrade in a landfill, and they are not accepted by recyclers as PLA ruins the recycle stream of PET plastics. They must be composted in a commercial or municipal composting site….anyone know where they are?
Additionally, many reports indicate that in addition to causing our food process to rise, the equipment and chemicals used to produce food based bio-fuel may be increasing pollution.
We knew that there wasn’t going to be one “fix it all” answer and began to wonder if anything was ever going to be done. The problem was growing every day, more bottles were being manufactured and more bottles were accumulating in places where we didn’t need them.
We were wondering if “Earth Friendly Bottles” would ever be available?
That’s why we decided to do our part and started ENSO Bottles. We are partnering with other companies to offer a PET plastic bottle that will biodegrade, compost or recycle.
Our bottles can be produced in a clear or colored version, however, clear version isn’t quite as clear as current PET plastic bottles but then again that’s one way to identify our earth friendly bottle.
ENSO is trying to achieve sustainability with our plastic bottles. Our goal is to make bottles that won’t have the adverse impact on our environment and are made from non food bio-fuels.
We haven’t started making them from bio-fuel but that’s high on our agenda and hopefully will be something we can offer in the future.
But for now, we offer a plastic bottle that is earth friendly…it’s just one step but if we all take just one step toward improving our planet….we will make a difference.
Hi,
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Thanks Again,
Oceansgreen