dimanche 8 février 2009

Feedback on oxo-biodegradables

Ci-dessous, le commentaire de Steve Mojo, Executive Director, Biodegradable Products Institute publié dans le dernier numéro de Packaging World Magazine. Ce commentaire fait suite à l’éditorial de Pat Reynolds (oxo-biodegradability, Packaging World Magazine, January 2009, p. 6).

Dans son commentaire Mojo, confirme les craintes de beaucoup et reprend plusieurs points qui ont déjà été mentionnés dans Pakbec (voir dossier Oxo-biodégradable).

First, while many of your readers may not be familiar with the term “oxo-biodegradable,” the concept and materials are not new. The use of transition metals to promote oxidation is very well known. Patents in this area trace back decades. Many converters, in fact, have already tried and rejected these technologies.

Second, no scientific data has ever been presented to show that oxo-biodegradable additives will render plastics completely biodegradable under the anaerobic conditions found in landfills. This is reinforced by a recent NAD finding that the claims of one oxo-biodegradable supplier, Dallas-based GP Plastics, were not supported and did not meet the requirements of the Federal Trade Commissions Environmental Marketing Guides. This from a December 8, 2008, press release: “National Advertising Division of the Council of Better Business Bureaus (NAD) noted that the advertiser’s claim that PolyGreen bags are disposable through ordinary channels should similarly be supported by competent and reliable scientific evidence that the entire plastic bag will completely break down and return to nature…within a reasonably short period of time after customary disposal. However, NAD determined that the evidence in the record did not support that claim.”

Third, “recyclability” claims of oxo-biodegradable plastics are also unsubstantiated. In fact, large recyclers of polyethylene—Trex (http://www.trex.com/) is a good example—have expressed concerns about the negative impacts that oxo-biodegradable additives will have on recycling. In September of last year, Trex put it this way: “Unless and until the long-term durability testing concludes that the oxo-biodegradable polyethylene (OBPE) will not have an adverse effect on our product, Trex cannot support the introduction of OBPE materials into traditional recyclable Polyethylene streams.”

On the PET front, the Association of Postconsumer Plastic Recyclers issued this cautionary warning on oxo-biodegradability: “APR asks those who advocate and specify degradable additives to consider the sustainability implications of degradable additives that lower the functionality of recycled post consumer plastics when included with recyclable plastics. Degradable additives that weaken products or shorten the useful life of durable plastics would have a strongly negative impact on post-consumer plastics recycling. APR provides its PET Critical Guidance and Applications Guidance to evaluate PET bottle innovations.”

Biodegradable products and packaging are simply not the panacea to solid waste that many suppliers claim, especially when these products wind up in landfills. The work of William Rathje (author of Rubbish) shows that today’s landfills are designed to preserve our trash, not make it magically disappear through “biodegradation.” Rathje found large amounts of readily “biodegradable” materials during his 15 landfill excavations throughout North America in the 1980’s. For example, he notes 40-year-old newspapers that were still legible and “fresh looking” lettuce that was 5 years old. I would urge that your readers familiarize themselves with his work in order to better understand what does and does not happen in a landfill.

In conclusion, there should be emphasis on the creation of infrastructure to manage “compostables” rather than search for “biodegradable” alternatives that will wind up in landfills. Perpetuating the misconception that oxo-biodegradadable materials will fully biodegrade in a landfill works against the Reduce, Reuse and Recycle philosophies that have been developed over the past two decades. I would urge packaging professionals to continue to focus on solutions that can be diverted from landfills and incinerators to recycling and composting facilities. This would be in keeping with the Environmental Protection Agency’s Solid Waste Hierarchy.

2 commentaires:

Max a dit…

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. 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.

Now all we need is for a lot of beverage companies to start using earth friendly plastic bottles.

Anonyme a dit…

Mr Mojo is correct on one thing :patents on oxo are quite old. So what ? . Oxo-biodegradable plastics have in fact been used successfully in packaging and in agriculture since 1974.
Plastics made from a blend of starch and polyethylene are nearly as old as oxo
Some further comments .

The biodegradation of a products containing starch or polyester in anaerobic condition (absence of oxygen ) generate methane which is a greenhouse gas 23 times more powerful than C02.
This is not what you want !!.
Paper from 100 years has been found buried in the soil in anaerobic condition!
Mr MOJO recognises that oxo-biodegrade in aerobic condition, which is correct.
More and more studies and independent tests are showing that, when an oxo is fragmented, in the soil, or under condition of compost like the ISO 14855 or ISO 14852 (aqueous media ) there is biodegradation and CO2 conversion so long as oxygen is present. Customers who intend to use oxo product should ask the provider of the additive to provide evidence of the good behaviour of the additive in that condition Like in any business there is good and bad product. Good formulation and bad formulation are found for every product being put on the market .

Independent lab tests using FTIR or GPC measurement of product buried in the soil in presence of oxygen ,exposed to the light or only to the heat are showing increase of carbonyl index and decrease of molecular weight down to less than 5000 with no formation of gel (according to ASTM 6954-4). Again customers who are planning to use oxo should ask the provider of additive to show test results of the additive . Recently Emo Chiellini from PISA university has shown biodegradation of an oxidised film in water .

Concerning recycling, an oxo-biodegradable is made of greater than 99% of PE or PP why is this not recyclable ? Unfortunately this is not possible with the PLA or any of the products made of starch/polyester due to their incompatibility with carbon-chain plastics, In this case a segregated collection has to be set up .

A study done by ADEME Dec 2007 (part of the ministry of the environment ) in France comparing plastics from various origins in different application and evaluating the end of life concludes as follow :

Synthèse d’études environnementales sur des plastiques de différentes d’origine (renouvelables et fossiles) :
« L’origine renouvelable des plastiques n’apparaît pas en l’état actuel des connaissances et du développement des filières en fin de vie comme un atout environnementale fortement affirmé comparativement aux résines d’origines pétrolières »(manque de connaissances stabilisées,production,surfaces utilisées….)
• Le traitement final des déchets contribue peu au bilan environnemental
• La valorisation énergétique ressort comme la filière la plus adaptée d’un point de vue environnemental pour les polymères d’origine renouvelable .
• C’est le recyclage qui permettrait la plus grande amélioration environnementale d’un emballage plastique .

The current level of knowledge on plastics made of bio based material and the current end of life structure of our country may not bring any significant environmental advantage over the plastic made of fossil resources (lack of knowledge, production, land occupation..)
• The type of end of life doesn’t contribute significantly to the positive effect in term of environment
• Incineration is the most positive in term of environmental benefit for the bio based plastics
• Recycling is the most beneficial end of life for oxo-biodegradable plastics
oxobiodegradable plastics do not go again these obvious assessment