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.