Labeling confusion, skepticism about functionality, end-of-life issues, and a higher price compared with traditional plastics all continue to pose challenges. Asda’s reversal is illustrative of the challenges bioplastics face. A few years ago when the Wal-Mart-owned company made its announcement, supermarkets were full of enthusiasm for bioplastics. Today they are adopting a more measured approach.
Bioplastics and end-of-life issues
Bioplastics promise a variety of environmental benefits, from renewable resource usage to carbon savings. When plastic packaging is difficult to collect and recycle there seems an obvious advantage to using biodegradable material instead. But the benefits are wholly dependent on appropriate end-of-life treatment. Even if consumers were educated about bioplastic end-of-life issues, the infrastructure needed to properly dispose of the materials is more often than not unavailable.
Like most traditional plastics, bioplastics can be recycled and incinerated for energy recovery. Many bioplastics are also compostable. However, while industrial composting is an end-of-life option in a few European countries, in most regions the infrastructure does not exist. In reality, most bioplastics, an estimated 86 percent, are entombed in landfill where they do not receive sufficient moisture, oxygen and microbial contact to biodegrade.
“Supermarkets misunderstood the infrastructure needs of biodegradable plastic,” says John Williams, technology transfer manager for polymers and materials at the UK-based National Non-Foods Crop Centre (NNFCC).
In December, 2008, Packaging Digest called “biodegradable” the “single most misused and misunderstood word used today in the packaging arena.”
To complicate matters, the word "bioplastics" is no longer limited to biodegradable or compostable plastics made from natural materials such as corn or starch. Bioplastics also include petroleum-based plastics that are degradable, renewable resource-based plastics that are not necessarily biodegradable, and plastics that contain both petroleum-based and plant-based materials, which could be biodegradable or not.
“Biodegradable has really turned more into a marketing term,” says Anne Bedarf, a project manager with the Sustainable Packaging Coalition (SPC), a Charlottesville, Va., nonprofit industry advocacy group.
“It is far better to focus on giving our customers less packaging, along with reuse and recycling,” says Asda packaging buyer Shane Monkman. “We’ve got some fairly big concerns that we’ve been unable to get satisfactorily answered.”
A comprehensive life-cycle study of plastic bags carried out by the NNFCC found that environmental benefits of bioplastic bags are achieved only when mass marketing is “coupled effectively with disposal routes based on energy-from-waste (incineration) or municipal composting.”
Chairman of trade body European Bioplastics Harald Kab says, “Bioplastics using renewable feedstock do offer an intrinsic reduced carbon footprint. But life-cycle analysis is so complex, it isn't really a good tool for communication.”
For instance, when one compares composting of the starch-based bioplastic Plantic and landfilling your traditional petroleum-based polyethylene terephthalate (PET), the bioplastic is indeed ‘greener,’ emitting half the CO2 of PET. However, Plantic is one of the few bioplastics that will indeed break down in landfill and release methane in the process. So if even 70 percent of the Plantic reaches landfill its lifecycle emissions will be 50 percent greater than landfilled traditional petroleum-based plastic like PET.
So while bioplastics often offer substantial environmental gains over conventional materials, much depends on their chemical makeup and whether they end up being landfilled, incinerated or composted. Moreover, bioplastics can contaminate conventional PET recycling. If just one polylactic acid (PLA) bottle, a bioplastic made of corn starch or sugar, is thrown in with 1,000 PET bottles, it can render the whole batch useless, according to Mark Burstall, chair of the British Plastics Federation’s Recycling Council.
When the price of oil peaked at $150 per barrel in mid-2008 retailers and manufacturers began to discontinue use of petroleum-based materials and look seriously at the use of non-petroleum-based products, like many (but not all) bioplastics.
For instance, Cereplast, the US-based manufacturer of bio-based plastics that announced this month with much fanfare that it would transform algae into bioplastics, has lost more than $25m in the last two years and has needed to patch together additional financing to stay in business. The firm also has decided to suspend its manufacturing operations in California.
Metabolix, the US-based bioscience company, has lost more than $60m in two years, according to Plastic News. The company’s joint venture with agriculture giant Archer Daniels Midland to build a commercial plant in Clinton, Iowa has been delayed twice and is slated now to occur at the end of the calendar year.
The mega-retailer Wal-Mart’s sustainability index, by which it will reportedly judge products in such areas as energy and CO2 emissions, material efficiency and natural resources, has not so far succeeded in driving Wal-Mart supplier/manufacturers toward bioplastic packaging.
Many manufacturers who were early adopters are standing by their use of bioplastics in anticipation of future legislation mandating a push toward renewable materials. "We expect new legislation for bioplastics around organics recycling in Canada and the US in the coming years," says Keith Edwards, biodegradable plastics business manager for German chemical giant BASF.
Japan’s Fujitsu, the first computer maker to use biodegradable plastic, sees its commitment as a long-term strategy. “In the future, motivation will be higher than now, I think,” says Michinori Kutami, general manager of Fujitsu’s sustainable development planning division. Governments need to encourage companies to use bioplastics with green procurement policies and lowered taxes, he says.
Source: Ends Report, March 31, 2009, Modplas.com, Plastic News
Some bioplastics still lack heat resistance, impact resistance and barrier properties. "Since many of the current bioresins in homopolymer form cannot provide all of the benefits of petroleum-based resins, blends may be required to meet the performance specifications," says Paul Iacobucci, manager of high polymer specialties at US-based AkzoNobel Polymer Chemicals.
The next few years will see the introduction of plant-derived but non-biodegradable bioplastics that are functionally and chemically identical to their oil-derived counterparts. With several large-scale plants slated to open in Brazil and elsewhere in the next few years, these sugar-cane ethanol alternatives look set to take off and could overshadow biodegradable bioplastics.