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The myth of biodegradablility; in plastics, science still eludes usThe myth of biodegradablility; in plastics, science still eludes us

Biodegradability. It seems that this word has California State lawmakers - and the State's Attorney General - rather hung up. Well, it's got a lot of people hung up including consumers, and even those in the plastics industry.

Clare Goldsberry

November 4, 2011

4 Min Read
The myth of biodegradablility; in plastics, science still eludes us

It seems that many believe if the word "biodegradable" appears on a plastic bottle or package of any kind, it provides automatic permission for people to become litterbugs. In 2010 at the Society of Plastics Engineers (SPE) Thermoforming conference, Ramani Narayan, a professor at Michigan State University, acknowledged that "The problem is that people are claiming that all you do is put in an additive into the plastics and the material will magically disappear," noting that "biodegradable" is a "misused and abused" term. "Recycling and waste to energy are the best use of plastics waste - give up the biodegradability myth."

Everyone involved in this whole issue seems to agree on one thing: What we need is an end-of-life strategy. What no one seems to be able to agree upon is just exactly what that strategy is. Is it recycling, particularly of PET bottles? Is it composting? Is it finding a means of making plastic packaging truly biodegradable in any environment, including along a roadside out in the open? Or, do we put plastic waste to good use through waste-to-energy methods - in other words burn it as fuel like we do coal to produce electricity. As a fuel source, plastics has as many or more BTUs than coal.

Danny Clark, president of ENSO Bottles, admitted that their PET bottles, which have been proven through scientific testing to be both biodegradable and recyclable in the PET recycling stream, are not a "magic bullet" solution to a huge problem. We hear that word "magic" used a lot, when in fact we need to use the word "science" on which to base the whole issue of biodegradability and compostability.

The Biodegradable Products Institute (BPI), in a release on May 13, 2011, noted that BPI performed additional testing of AquaMantra's ENSO PET bottles at a second lab, Organic Waste Systems, using ASTM 5511. After 45 days, the test was suspended because no biodegradation was observed. "Specifically, the positive control achieved 85% after 15 days and finished at 87.3% at the end of the test. The PEST sample showed no biodegradation during the entire 45-day test period," said the release.

Conditions must be optimized for biodegradability and compostability. If the conditions aren't right, no degradation or compostability will take place. As Narayan said in his SPE presentation, "All of this biodegradable stuff sounds good. The public loves it! But I ask, in what environment will this degrade? Define 'environment.' The word 'biodegradable' means nothing. Time? Eventually, it will biodegrade, but when? Is some biodegradability better than nothing? No! There are health and environmental issues connected with biodegradability. It's all or nothing - must be defined in terms of the environment and time."

Carbon is carbon

Clark noted in a telephone interview that even if something takes five years to biodegrade, that's better than a thousand years. But is it? If we can recycle the PET today into new products, or use it in waste-to-energy to create tomorrow's electricity, isn't that better than letting PET bottles and packaging lay around - even if it's laying around in a "biodegradable" environment for five years or in a compost facility for several years, awaiting nature's action before it's useable? After all, as has been noted by industry critics of biodegradable plastics, "Nature's processes don't apply to industrial processes." Plastics is made through an industrial process, and adding a bit of PLA or other products isn't going to turn plastic inert via nature's processes. Carbon is carbon, no matter if it comes from coal or plants, say critics of biodegradability. After all we live in a carbon-based world.

A proponent of total recycling of PET, wrote to me recently commenting on Coke's "Plant Bottle", noting that the "Plant 'Boggle' would contribute absolutely zero to the major challenge that faces the survival of the single-use beverage bottle - the giant mess that used bottles create each and every day. Recycling is the only answer," this person wrote. "Using recycled material eliminates landfill, reduces carbon-footprint, eliminates land and ocean litter, and significantly reduces the use of non-renewable resources. In other words, it cleans up the mess in an environmentally friendly way. Biodegradables are nothing better than a destructive and dangerous joke."

It's doubtful that banning the use of the word "biodegradable" will solve the problems of plastics' end-of-life. And despite all the testing of the BPI and the Plastics Environmental Council (PEC), the masses aren't generally interested in the scientific facts. They just want the litter to go away. It will be up to those in the business of end-of-life in plastics to determine the most cost-effective, efficient and profitable way to achieve that.

About the Author(s)

Clare Goldsberry

Until she retired in September 2021, Clare Goldsberry reported on the plastics industry for more than 30 years. In addition to the 10,000+ articles she has written, by her own estimation, she is the author of several books, including The Business of Injection Molding: How to succeed as a custom molder and Purchasing Injection Molds: A buyers guide. Goldsberry is a member of the Plastics Pioneers Association. She reflected on her long career in "Time to Say Good-Bye."

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