What “Bio” Really Means
by Jennifer Berry
Published on February 8th, 2010
9 Comments
In the ever-changing world of consumer products, “bio” is gearing up to be the new buzzword (or prefix – take your pick) of the decade.
More and more products are hitting the shelves that are made of bio-based materials and/or are biodegradable. Simultaneously, confusion and questions about what to do with these products are rising at the same rate which they are landing in our grocery carts.
What do these terms mean? And more importantly, how do they affect you? Earth911 hit the streets to find out just that – and ended up learning a whole lot more.
Warning: This article is about to get a bit technical. But, we promise to distill it down the basics of everything you need it know. Put on your thinking caps!
Definitions You Have to Know
So, let’s start with a few terms you need to know:
Bio-based plastics or biopolymers – These are plastics made with materials that can be grown and are renewable. “‘Bio-based plastics’ means it’s made from a raw material that’s a renewable material,” said Keith Christman, managing director of plastics markets for the American Chemistry Council (ACC). Some bio-based plastics can be recycled in our current system, while others cannot.
Products carrying the term "biodegradable" are typically only compostable in a commercial composting system. Photo: Amanda Wills, Earth911.com
Biodegradable – Some materials are biodegradable, meaning they are capable of being decomposed by the action of biological agents, especially bacteria. But don’t confuse these first two terms. “Some bio-based materials are not biodegradable,” Christman added.
For example, according to Christman, Dow is producing ethylene from sugar cane (used to make polyethylene or a component of plastic #1), and the material is recyclable in today’s current recycling stream, but not biodegradable. Most biodegradable plastics cannot be recycled in the current stream.
Compostable – This term implies that a product will break down in a composting environment (more to come on this), but typically implies that a product should be composted in an industrial facility, not at home. There are new products on the way that may defy this particular aspect of “compostable,” but for our discussions, keep this in mind.
Life cycle assessment – Also referred to as an “LCA,” these reports look at various aspects of a product’s production, such as solid waste, energy consumption and greenhouse gas (GHG) emissions. These reports, while they vary product to product, typically give us a full-circle look at what the overall impact really is of a product’s manufacturing.
Polylactic acid – Also known as “PLA,” this material is a bio-based plastic that is typically biodegradable in a commercial composting system. It is one of the most prevalent biopolymers on the market currently.
These concepts represent a wide array of applications and innovation in the plastics market today. “A lot of these things show that plastics are innovative. They are carbon-based materials and can be made from a variety of carbon materials.
“In the U.S., we traditionally use natural gas,” Christman said, noting that approximately 79 percent of the plastics manufactured in the U.S. are made from this particular fuel source. And while biopolymers and biodegradable materials still constitute a fraction of the overall market, their presence is growing.
How Things Biodegrade
With all this discussion about “biodegradable,” the take-home message is that we should just be able to leave a bottle out in a park or bury it in the yard and it will decompose, right? Well, not exactly.
“When the consumer hears ‘biodegradable,’ often times they think it’s a material that you can throw out the window of your car and after one good rain, it will be back to nature, and it will fertilize the roadside,” said Richard C. Bopp, senior material scientist for Natureworks, LLC, one of the leading producers of PLA.
“Saying ‘biodegradable’ is not specific enough to be useful, and it leads to all kinds of misunderstandings,” he added.
Left to its own devices, PLA will not simply biodegrade on its own – which may be surprising, but is actually a benefit. “Thank goodness it’s that way [...] Otherwise you’d have a stability problem with your plastic – it’s like things going bad in your refrigerator,” said Bopp. Imagine mold growing on your cell phone, and you’ll understand why the basic concepts of “biodegradable” (a la the now-fuzzy fruit from last week’s lunch) don’t apply here.
So how does PLA actually biodegrade? Here’s how it works, according to Bopp:
Biodegradable products are typically derived from natural, plant-based ingredients. Flatware made from potatoes, corn and wood is popping up at grocers around the country. Photo: Amanda Wills, Earth911.com
- PLA cannot be metabolized by microbes. But the lactic acid, which is half of its molecular unit, can very easily be broken down.
- In the environment of a compost pile, which is typically around 60 degrees Celsius (140 degrees Fahrenheit) and 90 percent relative humidity, bonds in the PLA molecule are susceptible to a process called “hydrolysis,” which means being broken down by water.
- Because of this, water molecules come in and sever these bonds, ultimately freeing the lactic acid in the PLA molecule, meaning the microorganisms in the pile now have food to consume.
- The lactic acid is metabolized by the microorganisms, and water and CO2 are what remain from the original plastic.
According to Bopp, these biodegradable properties make more sense in some plastic applications over others. “I often like to say ‘why would I want to turn a perfectly good piece of plastic into dirt?’ [...] Well, I’d want to turn it into dirt if the cost for recovery for recycling was just so high that it didn’t make sense to recover it as a plastic.
“For example, if I use the PLA for plates, knives, forks and spoons [...] it may not make environmental or economic sense to recover dirty plastic covered with rotten food. It may make more sense, as it’s combined with paper napkins, paper cups, food waste, to compost it. And especially at a place like a theme park where you have gardens and use that for landscaping, it makes a lot of sense to compost bioplastics in those situations,” he said.
And with today’s PLA, what would constitute a less meaningful use of the material?
For illustrative purposes, Bopp uses the example of the instrument panel on a car’s dashboard. “Of course, it’s a double-edged sword, because if you have an instrument panel in a car made out of Ingeo PLA, as it is today, and it’s parked in Houston in the summertime, the interior of that car can get awfully close to [the conditions in] a compost pile,” he said. “For every 10 degrees Celsius (50 degrees Fahrenheit) increase in temperature, most reactions double in rate, so temperature is very important. I’m not saying PLA will never be used for an instrument panel, but we’ll have to figure out some stabilization developments.”
What’s the Holdup?
So, to recap so far, we’ve learned the basics of what constitutes a bio-based material and how breaking down PLA works. And, we can grow all of the materials we need for plastic right here at home in the U.S. So why isn’t all plastic made out of plants?
Getting to a Commercial Composter
One major hurdle right now is that finding a commercial composting facility is difficult, as they are are not as widely available and few cities across the U.S. have composting services. And, according to the National Resource Defense Council (NRDC), only 8 percent of Americans compost their waste, including residents in cities like San Francisco and Seattle, where composting is part of the general waste pickup.
“In terms of getting products to a commercial composting system in the U.S., there’s only a handful of communities that have collections for those kinds of materials right now,” Christman said.
“There’s no silver bullet,” Bob Lilienfeld, editor of the Use Less Stuff Report (ULS) tells Earth911. “There isn’t a single product that solves every issue out there.”
Since PLA is not recyclable in our current system, these bottles can end up getting thrown out. Lilienfeld notes that in order for anything to break down, including biopolymers, light, water and heat are required – exactly elements that “landfills are designed to keep out,” so they won’t break down as they are designed.
Overall LCA Impacts
The cumulative effect of the production of biodegradables and biopolymers are important as well.
According to Lilienfeld, in terms of solid waste, energy consumption and GHG emissions, “There’s really no biopolymer that outperforms a nonbiopolymer on those LCA measurements.You have to constantly balance the functionality of the product, the cost of that product and then finally the perceptions of that product [with its overall lifecycle impact].”
On the other hand, Bopp notes that “PLA has the lowest carbon footprint and the lowest use of fossil fuel energy of all the commercial plastics,” through the process of pelletizing the plastic – the step before the plastic is molded into an actual product.
“While these are important areas of innovation, [the use of PLA] needs to be teamed with products that are most suited to their applications [...] and looking at their full lifecycle inventories,” said Christman.
“The other part that’s important there is the use of lifecycle inventories to make sure they [PLA plastics] do reduce environmental impact or not,” he adds. “There are cases where you can put more energy into making a renewable material into a package than you can save.”
What Really Matters
No matter which side of the fence you’re on, the most important considerations with these materials is to understand what they are and how you can (or can’t) use them in your area.
“The overall theme is that [bio-based materials and biodegradables] are innovative, but we need to be careful about it and we need to do some careful analysis,” said Christman.
Lilienfeld agrees. “Ultimately, like it or not, it’s all about the numbers. It’s not about making people feel good. Sometimes, natural gas may be the better source. On the other hand, if something grown domestically reduces our need for foreign oil and our need to defend ourselves, then that’s an important consideration too,” he says.
“Nature doesn’t care if you feel good about what you do. If what you do actually increases GHG gases [...] it’s ultimately a negative.”
If you use bio-based materials that can be recycled in today’s current stream, such as Coke’s new Plant Bottle or Dow’s sugar cane-based resins, then the answer is simple: Toss it in the recycling bin. But if you do buy compostable plastics, be sure to seek out an industrial composting facility near you.
- American Chemistry Council(02/04/2010). "Phone Interview with Keith Christman" By Jennifer Berry.
- Natureworks, LLC(02/04/2010). "Phone Interview with Richard Bopp" By Jennifer Berry.
- Use Less Stuff Report(02/05/2010). "Phone Interview with Robert Lilienfeld" By Jennifer Berry.
Leslie Harty
posted on February 8th, 2010 at 1:10 pm
There are several problems with PLA, the biggest being that when you examine the life cycle analysis and add up the fossil fuels they use, in reality they use MORE fossil fuels for making the product than plastic does. That really seems to be a big discrepancy don’t you think? They off-set this by buying energy credits. But if you had to chose between plastic and PLA, why pick the one that uses more fossil fuels? It makes no sense! The second problem is what was noted in this article- they will only break down in commercial and municipal composts of which there are only 88 in the entire US. So more than likely they end up in landfills where they last as long as normal plastics-400 yrs or so. Lastly, has anyone read up on the GMO/GE corn they use? This corn has been shown in a recent article to cause heart, liver, and kidney damage when eaten by rats in as little as 41/2 months. They put pesticides (Bt) and weedkillers into the corn (Monsanto) by altering the genes of the plant and inserting it into the DNA.One study even showed the new DNA had new proteins in them called prions (improperly folded proteins). These prions are found in what is called “mad cow” diseases. Until someone can prove these prions , which can survive high heat, are not in the corn used in making PLA,are we not in the same danger we face with the leaching of PBA’s in plastics?I know of no studies done yet on this subject.
Max
posted on February 9th, 2010 at 10:49 am
Leslie, thank you for your excellent comments. There is so much money (private and government subsidies) being used to sell the concept of PLA (and ethanol) that I’m afraid the public is going to buy it hook, line and sinker. You can read blog after blog about how terrible something is because it is made from petroleum products; yet they still get in their cars, planes and trains and think nothing of burning up a scarce non-renewable resource like petroleum. I believe we all need to become more educated on what it really means to be “green” or “sustainable.” It might sound like the best idea ever to make things from renewable plants and it could be….but let’s not use land that should be growing food grade crops to make our fuel and plastics. I think a better alternative would be to use algae for manufacturing ethanol and plastics.
We need to say no to genetically modified food crops for the production of ethanol, PLA plastic and high fructose corn syrup all of which have the potential to destroy our food supplies.
Max
Jared
posted on February 9th, 2010 at 12:42 pm
I credit the author with doing an excellent job of relating a complicated topic in a very lucid manner.
The comments by Max and Leslie do a good job of highlighting how the concept of sustainable really needs to be thought through. For something to be truly sustainable, a cyclical relationship between producing a product and then having the waste be reclaimed with no net loss of raw materials is paramount. Furthermore, the energy needed for the processing should be the only net input and this should ultimately be derived from a renewable energy source. Until we have plastics that are derived from a biomaterial, processed using renewable energy, and returned to the original source, the concept of a truly sustainable way of living will escape us.
I’m not fully aware of the potential pitfalls of the GM corn used to provide the raw materials, so I will refrain from commenting in this area.
Dinesh Thirupuvanam
posted on February 9th, 2010 at 6:51 pm
Agreed – Thanks for breaking down a rather complex topic. I’m aware of most of this, but I know many folks aren’t (thus a simple synopsis is always helpful). I also run a green purchasing co-operative, http://www.VivBizClub, and thus am always curious to learn more. A few questions:
1) Jennifer – do you have a list of the cities in the US that offer hauling of compost to the citizens and businesses. FindAComposter.com is helpful for locating a composting facility, but I’m looking to specifically identify municipalities that haul as well.
2) Leslie – do you have more details on the life-cycle analysis of PLA. I’d really like to be more well read here.
3) Leslie – if you have any further information or know or any ongoing studies regarding GMO corn used to make PLA (or potentially leaching of harmful materials from PLA based products), I’d be curious to learn more.
lciani
posted on February 11th, 2010 at 10:39 am
1) There is no DNA in polymers. PLA is a polymer, so there is no GMO, no DNA information in this or any plastic. Even if GMO corn is at the start of the chain that leads to PLA articles sold on the market, those products will not contain any GMO nor will it contain prions. Buy PLA cups or plates, take it to the chemical lab of the nearest campus and ask them to check for GMO/prions…
2) NatureWorks have put together an impressive LCA study on PLA which you can get from their website.
Dinesh Thirupuvanam
posted on February 11th, 2010 at 4:58 pm
Iciani – Thanks for the follow-up. Will check out the natureworks LCA study. Also, I like your point on GMO/prions testing at a local campus. Actually jogged my memorty that I have a good friend who’s a Chemical Engineering PHD at Stanford – may ask him to do this for me. If I do I’ll try and share the results back here.
Simiya
posted on February 11th, 2010 at 5:55 pm
Greetings
This is a good article making it real simple for the grass root.What we have learnt is very usefulfor the group.
Thanks Jennifer Berry
Kate Lewis
posted on February 17th, 2010 at 8:41 am
Excellent coverage of these issues and related comments, thank you all.
If you’re taking time to research and learn more, I recommend you check out the US Department of Agriculture’s (USDA) BioPreferred program. It’s a USDA-led initiative designed to increase the purchase, use, and evaluation of biobased products, including biopolymers.
USDA defines biobased products as those composed in whole or in significant part of biological ingredients; forestry or renewable agricultural materials — including plant, animal, or marine (e.g. algae) ingredients. USDA identifies more than 4,500 biobased products (products must meet/exceed minimum biobased content) in 42 product categories as “BioPreferred designated” products.
Are biobased products ‘greener’? We’ve begun the dialogue on the environmental assessment of these products via a public meeting held in Jan 2010 – meeting materials are available on the home page of our website.
Kate Lewis, USDA
Deputy Program Manager, BioPreferred
laura Rodriguez
posted on February 19th, 2010 at 11:02 pm
This is an interesting and enlightening discussion. I too appreciate all who are looking into these issues. I have been looking into the benefits of polystyrene (#6 plastic), and as of yet have not been disappointed. If you grew up in the seventies, as I did, this sounds counter-eco, but the product is actually 95% air, and so it uses next to nothing in material, and can be produced without harmful emissions, and recycled into other plastics. I wonder sometimes as I listen to the “bioplastic” if in some ways we are still back in the seventies, and considering littering practices, or if many don’t have a complete understanding of landfill design and function in our country. California now has only 3 landfills which are designed to allow biodegradation, all others are specifically designed to stop biodegradation. If I could for a moment equate the ecosystem to the body, and ask why there is such a push to use land and plants to produce one-time use products that we feel good about tossing. We wouldn’t feel good about good about cutting out our lungs (please exuse my crude metaphor) just because it would end up in the colon. What is the attraction to onetime use (bio-sources), when we could reuse petro-based plastics for years in a reusable/recycled loop, and in many cases use fewer resources to produce and recycle and transport the many products in the plastic stream. Face it, much like metals, we are stuck on the properties and performance of plastic products. I’m sure there is a place for bio-plastics in the big picture, but be careful not to use it for a bandaid to cover our guilt. I’m glad to see people fully considering the options and the ecological costs of our many options, but in my mind, using any natural resource only once is not a sensible goal. If we use any resource, I would like to see it remain in use for years to come, so that we do not have to go back for more. Unless there’s something I’m unaware of, soil is the only reuse opportunity for “bio-plastics”. Is there a shortage of soil? There is a fast growing market for recycled plastic products and the costs of recycled raw materials is rising because of this demand. Is the call for soil going to sustain this push to use bio-plastics. Re-use, ultimately, may be the only way we can use up less.