Bioplastics – are they the answer?

16 04 2012

From Peak Energy blog; August 27, 2008

From last week’s blog post, we discussed how bio based plastics do indeed save energy during the production of the polymers, and produce fewer greenhouse gasses during the process.  Yet right off the bat, it could be argued that carbon footprints may be an irrelevant measurement,  because it has been established that plants grow more quickly and are more drought and heat resistant in a CO2 enriched atmosphere!   Many studies have shown that worldwide food production has risen, possibly by as much as 40%, due to the increase in atmospheric CO2 levels.[1] Therefore, it is both ironic and a significant potential problem for biopolymer production if the increased CO2 emissions from human activity were rolled back, causing worldwide plant growth to decline. This in turn would greatly increase the competition for biological sources of food and fuel – with biopolymers coming in last place.[2]  But that’s probably really stretching the point.

The development of bioplastics holds the potential of renewability, biodegradation, and a path away from harmful additives. They are not, however, an automatic panacea.  Although plant-based plastics appeal to green-minded consumers thanks to their renewable origins,  their production carries environmental costs that make them less green than they may seem.  It’s important to remember that bioplastics, just like regular plastics, are synthetic polymers; it’s just that plants are being used instead of oil to obtain the carbon and hydrogen needed for polymerization.

It’s good marketing, but bad honesty, as they say, because there are so many types of plastics and bioplastics that you don’t know what you’re getting in to;  bioplastics are much more complicated than biofuels.  There are about two dozen different ways to create a bioplastic, and each one has different properties and capabilities.

Actually the term “bioplastic” is pretty meaningless, because some bioplastics are actually made from oil – they’re called “bioplastics” because they are biodegradeable.  That causes much confusion because plastics made from oil can be biodegradeable whereas some plant-based  bioplastics are not. So the term bioplastics can refer either to the raw material (biomass) or, in the case of oil-based plastic, to its biodegradability.  The problem with biodegradability and compostability is that there is no agreement as to what that actually means either,  and under what circumstances

You might also see the term “oxo-degradable”.   Oxo-degradables look like plastic, but they are not. It is true that the material falls apart, but that is because it contains metal salts which cause it to disintegrate rapidly into tiny particles. Then you cannot see it anymore, but it is still there, in the ocean too. Just as with conventional plastics, these oxo-degradables release harmful substances when they are broken down.

Let’s re-visit  some of the reasons bioplastics are supposed to be an environmental benefit:

  • Because it’s made from plants, which are organic, they’re good for the planet.  Polymer bonds can be created from oil, gas or plant materials. The use of plant materials does not imply that the resulting polymer will be organic or more environmentally friendly. You could make non-biodegradable, toxic plastic out of organic corn!
  • Bioplastics are biodegradable. Although made from materials that can biodegrade, the way that material is turned into plastic  makes it difficult (if not impossible) for the materials to naturally break down.  There are bioplastics made from vegetable matter (maize or grass, for example) which are no more biodegradable than any other plastics, says Christiaan Bolck of Food & Biobased Research.[3]  Bioplastics do not universally biodegrade in normal conditions  –  some require special, rare conditions to decompose, such as high heat composting facilities, while others may simply take decades or longer to break down again, mitigating the supposed benefits of using so-called compostable plastics material. There are no independent standards for what even constitutes “biodegradable plastic.”  Sorona makes no claim to break down in the environment; Ingeo is called “compostable” (though it can only be done in industrial high heat composters). Close studies of so-called degradable plastics have shown that some only break down to plastic particles which are so small they can’t be seen  (“out of sight, out of mind”), which are more easily ingested by animals. Indeed, small plastic fragments of this type may also be better able to attract and concentrate pollutants such as DDT and PCB.[4]
  • Bioplastics are recyclable. Because bioplastics come in dozens of varieties, there’s no way to make sure you’re getting the right chemicals in the recycling vat – so although some bioplastics are recyclable, the recycling facilities won’t separate them out.  Cargill Natureworks insists that PLA  can in theory be recycled, but in reality it is likely to be confused with polyethylene terephthalate (PET).  In October 2004, a group of recyclers and recycling advocates issued a joint call for Natureworks to stop selling PLA for bottle applications until the recycling questions were addressed.[5]  But the company claims that levels of PLA in the recycling stream are too low to be considered a contaminant.  The process of recycling bioplastics is cumbersome and expensive – they present a real problem for recyclers because they cannot be handled using conventional processes. Special equipment and facilities are often needed. Moreover, if bioplastics commingle with traditional plastics, they contaminate all of the other plastics, which forces waste management companies to reject batches of otherwise recyclable materials.
  • Bioplastics are non-toxicBecause they’re not made from toxic inputs (as are oil based plastics), bioplastics have the reputation for being non toxic.  But we’re beginning to see the same old toxic chemicals produced from a different (plant-based) source of carbon. Example:  Solvay’s bio-based PVC uses phthalates,  requires chlorine during production, and produces dioxins during manufacture, recycling and disposal. As one research group commissioned by the European Bioplastics Association was forced to admit, with regard to PVC,  “The use of bio-based ethylene is …  unlikely to reduce the environmental impact of PVC with respect to its toxicity potential.[6]

The arguments against supporting bioplastics include the fact that they are corporate owned, they compete with food, they bolster industrial agriculture and lead us deeper into genetic engineering, synthetic biology and nanotechnology.  I am not with those who think we shouldn’t go there, because we sorely need scientific inquiry  and eventually we might even get it right.  But, for example, today’s industrial agriculture is not, in my opinion, sustainable, and the genetic engineering we’re doing is market driven with no altruistic motive. 

If properly designed, biodegradable plastics have the potential to become a much-preferred alternative to conventional plastics. The Sustainable Biomaterials Collaborative (SBC)[7] is a coalition of organizations that advances the introduction and use of biobased products. They seek to replace dependence on materials made from harmful fossil fuels with a new generation of materials made from plants – but the shift they propose is more than simply a change of materials.  They promote (according to their website): sustainability standards, practical tools, and effective policies to drive and shape the emerging markets for these products.  They also refer to “sustainable bioplastics” rather than simply “bioplastics”.  In order to be a better choice, these sustainable bioplastics must be:

  • Derived from non-food, non-GMO source materials – like algae rather than GMO corn, or from sustainably grown and harvested cropland or forests;
  • Safe for the environment during use;
  • Truly compostable and biodegradable;
  • Free of toxic chemicals during the manufacturing and recycling process;
  • Manufactured without hazardous inputs and impacts (water, land and chemical use are considerations);
  • Recyclable in a cradle-to-cradle cycle.

Currently, manufacturers are not responsible for the end-life of their products. Once an item leaves their factories, it’s no longer the company’s problem. Therefore, we don’t have a system by which adopters of these new bioplastics would be responsible for recovering, composting, recycling, or doing whatever needs to be done with them after use. Regarding toxicity, the same broken and ineffective regulatory system is in charge of approving bioplastics for food use, and there is no reason to assume that these won’t raise just as many health concerns as conventional plastics have. Yet again, it will be an uphill battle to ban those that turn out to be dangerous.

A study published in Environmental Science & Technology traces the full impact of plastic production all the way back to its source for several types of plastics.[8]   Study author Amy Landis of the University of Pittsburgh says, “The main concern for us is that these plant-derived products have a green stamp on them just because they’re derived from biomass.  It’s not true that they should be considered sustainable. Just because they’re plants doesn’t mean they’re green.”

The researchers found that while making bioplastics requires less fossil fuel and has a lower impact on global warming, they have higher impacts for eutrophication, eco-toxicity and production of human carcinogens.  These impacts came largely from fertilizer use, pesticide use and conversion of lands to agricultural fields, along with processing the bio-feedstocks into plastics, the authors reported.

According to the study, polypropylene topped the team’s list as having the least life-cycle impact, while PVC and PET (polyethylene terephthalate) were ranked as having the highest life-cycle impact.

But as the Plastic Pollution Coalition tells us, it’s not so much changing the material itself that needs changing – it’s our uses of the stuff itself.  We are the problem:   If we continue to buy single-use disposable objects such as plastic bottles and plastic bags, with almost 7 billion people on the planet, our throwaway culture will continue to harm the environment, no matter what it’s made of.

The Surfrider Foundation

The Surfrider Foundation has a list of ten easy things you can do to keep plastics out of our environment:

  1. Choose to reuse when it comes to  shopping bags and bottled water.  Cloth bags and metal or glass reusable  bottles are available locally at great prices.
  2. Refuse single-serving packaging, excess  packaging, straws and other ‘disposable’ plastics.  Carry reusable utensils in your purse, backpack or car to use at bbq’s, potlucks or take-out  restaurants.
  3. Reduce everyday plastics such as sandwich bags and juice cartons by replacing them with a reusable lunch bag/box that includes a thermos.
  4. Bring your to-go mug with you to the coffee shop, smoothie shop or restaurants that let you use them. A great  way to reduce lids, plastic cups and/or plastic-lined cups.
  5. Go digital! No need for plastic cds,  dvds and jewel cases when you can buy your music and videos online.
  6. Seek out alternatives to the plastic  items that you rely on.
  7. Recycle. If you must use plastic, try to choose #1 (PETE) or #2 (HDPE), which are the most commonly recycled      plastics. Avoid plastic bags and polystyrene foam as both typically have very low recycling rates.
  8. Volunteer at a beach cleanup. Surfrider Foundation Chapters often hold cleanups monthly or more frequently.
  9. Support plastic bag bans, polystyrene  foam bans and bottle recycling bills.
  10. Spread the word. Talk to your family and friends about why it is important to Rise Above Plastics!

[1] See for example: Idso, Craig, “Estimates of Global Food Production in the year 2050”, Center for the Study of Carbon dioxide and Global Change, 2011  AND  Wittwer, Sylvan, “Rising Carbon Dioxide is Great for Plants”, Policy Review, 1992  AND  http://www.ciesin.org/docs/004-038/004-038a.html

[2] D. B. Lobell and C. B. Field, Global scale climate-crop yield relationships and the impacts of recent warming, Env. Res. Letters 2, pp. 1–7, 2007 AND L. H. Ziska and J. A. Bunce, Predicting the impact of changing CO2 on crop yields: some thoughts on food, New Phytologist 175, pp. 607–618, 2007.

[3] Sikkema, Albert, “What we Don’t Know About Bioplastics”, Resource, December 2011; http://resource.wur.nl/en/wetenschap/detail/what_we_dont_know_about_bioplastics

[4] Chandler Slavin, “Bio-based resin report!” Recyclable Packaging Blog May 19, 2010 online at http://recyclablepackaging.wordpress.com/2010/05/19/bio-based-resin-report

[6] L. Shen, “Product Overview and Market Projection of Emerging Bio- Based Plastics,” PRO-BIP 2009, Final Report, June 2009





Plastics – part 2: Why recycling is not the answer

5 05 2010

In Plastics, Part 1 (last week’s post; click here to read it) I tried to give a summary of why plastics are not such a good thing.  The Plastic Pollution coalition has a list of basic concepts about plastic.  Click here to read the expanded version:

  • Plastic is forever
  • Plastic is poisoning our food chain
  • Plastic affects human health
  • Recycling is not a sustainable solution

Yet there seems to be no end to our demand for plastics.   In one year alone, from 1995 – 96, plastic packaging increased by 1,000,000,000 lbs.  And despite recycling efforts, for every 1 ton increase in plastic recycling, there was a 14 ton increase in new plastic production.

I tried to explain some of the roadblocks to plastic recycling efforts.   We have all heard that recycling is good for the environment,  and it’s hard to argue with the intuitively correct reasoning that if we recycle we reduce our dependence on foreign oil, we conserve energy and emissions and we keep bottles out of the landfills.

And what about the lighter weight of plastic bottles?  Surely there are benefits in shipping lighter weight bottles  – giving plastic bottles a lower overall carbon footprint?  Well, here’s the thing:  there are environmental trade offs, just like in life.  Even if we accept that plastics are more carbon efficient than alternative materials (glass) in transportation, we’re still talking about vast amounts of carbon emissions.  Plastics use releases at least 100 million tons of CO2 – some say as much as 500 million tons – into the atmosphere each year.  That’s the equivalent of the annual emissions from 10 – 45% of all U.S. drivers.  Plastic manufacturing also contributes 14% of the national total of toxic (i.e., other than CO2) releases to our atmosphere; producing a 16 oz PET bottle generates more than 100 times the amount of toxic emissions than does making the same size in glass.  But the critical point is that it’s definitely cheaper to ship liquids in plastic rather than in glass.  And it’s also cheaper for manufacturers to use virgin plastic than a recycled plastic.

These rather alarming CO2 numbers could be much lower, we understand, if only Americans recycled more than the paltry 7% of plastic which is recycled today.  We could cut our usage of virgin material by one third – and that means an annual savings of 30 to 150 million tons of CO2.

So why aren’t Americans recycling more?  Although our plastic consumption has grown by a factor of 30 since the 1960s, recycling has grown by a factor of just two.  Is this just because we don’t take the time to separate recyclable plastics from general waste, or because we don’t take the time to throw the bottle into the proper recycling bin?  What about companies that use the plastic – they are not clamoring to spend more to use recycled plastic (again that bugaboo “cost”) so they continue to demand virgin plastic.

When Rhode Island enacted comprehensive recycling legislation in 1986, including bans on plastic bottles – the plastic industry responded by introducing their resin codes, in part (some say) to deflect attention from the virgin polyester production and encourage an environmental spin on the plastics.  The plastics industry’s  “chasing arrows” symbol surrounding a number (those resin codes) were “deliberately misleading” according to Daniel Knapp, director of Berkeley’s Urban Ore.  “The plastics industry has wrought intentional confusion with that symbol”, said Bill Sheehan, director of GrassRoots Recycling Network.  Unlike glass and aluminum, plastic has no system for recycling – no infrastructure to sell it, no markets to buy it, no facilities to make it.  “In short, the arrows led nowhere.”(1)

According to many, these codes just gave plastic an environmental patina, which the industry was quick to use.  “Several states have postponed or backed off from restrictive packaging legislation as a result of the voluntary coding system” – this gleeful statement from a 1988 newsletter of the Council on Plastics and Packaging in the Environment.

The industry’s critics say that it won’t do anything to support recycling.  Mel Weiss, an independent plastics broker, sees the industry focused on PR and not at all interested in recycling.  He says:  “the American Plastics Council (APC), a trade group representing virgin-resin producers, won’t do anything to support recycling. If they had a choice between selling one pound of virgin and 22 tons of recycled, they’d sell the virgin. All they’re doing is masking what they’re doing with an expensive ad campaign.”

Here’s the irony:  it was the veneer of recyclability – cultivated by the plastics industry – that led to this explosion of plastic use.

The plastics industry, spearheaded by the American Plastics Council (APC), has sponsored campaigns to convince the public that recycling is easy, economical and a big success.  They are a “responsible choice in a more environmentally conscious world”, according to the APC.  Between November 1992 and July 1993, the APC spent $18 million in a national advertising campaign to “Take Another Look at Plastics.” (Environmental Defense Fund, October 21, 1997, “Something to hide: The sorry state of plastics recycling.”)  Examples of how plastics “leave a lighter footprint on the planet” include the argument that plastic grocery bags are lighter and create less waste by volume than paper sacks, the industry said. And the fact that plastics are so lightweight and durable enables manufacturers to use less energy and generate less waste in production processes, plastic promoters said.

In addition to the American Plastics Council, the American Chemical Council (ACC) also spends millions to defend the chemicals produced by their members to make plastics. – including lobbying against any bills that would add a few cents to each bag or bottle to encourage returns and recycling efforts.    According to Lisa Kaas Boyle, Board Member of Heal the Bay, the ACC has hired the same advisors who defended the tobacco industry to formulate a strategy to promote and defend the petrochemical industry.  That strategy is based on preventing legislation to curtail single use plastics  (SUPs – i.e., soda bottles etc.) and to generate positive press on the promotion of recycling as the solution to plastic pollution.  This approach makes the industry look environmental while continuing with business as usual.

Because most manufacturers don’t take back their products, there’s often little opportunity to sell collected plastic. It is true that the West Coast  is blessed with domestic and overseas markets that have made recycling of #1 and #2 plastics – soda bottles and milk jugs – somewhat easier. But even here, metals and paper are the real money-makers.

“Plastics is the least profitable part of the business,” said Kevin McCarthy, regional recycling manager at Waste Management Inc.,  “and it may not even be fair to say that it is profitable at all.”

Like McCarthy’s operation, many recyclers will collect plastic only to meet contractual requirements from government agencies. The impetus to collect certain types of plastic comes from residents. But these plastics often have no market for reuse. Recyclers call it “junk plastic,”  – stuff that gets collected only “because residents wanted it collected because they watched the commercials on TV extolling the recyclability of plastic,” said one recycling official who insisted on anonymity.

In Europe, plastic recycling rates hover around 16.5%, largely because there are strict regulations from Europe’s “End of Life Directive”, in which manufacturers must take more responsibility for the processing of waste from their products.  In the U.S., efforts come largely from voluntary programs within companies, such as Wal Mart’s campaign to reduce the size of packages and increase their use of recycled materials.   The  U.S. government is highly unlikely to enact recycling legislation.  We in Seattle  voted last summer on a citizen sponsored plastic bag tax (we called it a fee)  of $0.20 per disposable bag coupled with a ban on Styrofoam.  The American Chemistry Council spent more than $1.4 million to defeat the bill – and they succeeded.

One aspect of recycling which is little known to consumers is the fact that almost all of the plastics we recycle, regardless of type, end up in China, where worker safety standards are virtually nonexistent and materials are sorted and processed under dirty, primitive conditions. The economics surrounding plastic recycling — unlike those for glass and aluminum — make it a dubious venture for U.S. companies.

(1)  Dan Rademacher, “Manufacturing a Myth: The plastics recycling ploy”, Terrain Magazine, Winter 1999








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