Hiya
Michael Stephen – who has not made his affiliation or interests clear – has left a comment that deserves to be shared here, but also requires our critical consideration. Michael has made four statements (given in
italics below), lifted from the website of the
Oxo-biodegradable Plastics Organisation:
1
It is not a good idea to ban plastic bags (See http://www.biodeg.org/Plasticbagbans.htm) but it is a good idea to make them oxo-biodegradable (www.biodeg.org), and Tesco are to be congratulated. These bags will harmlessly self-destruct if they get into the open environment.
According to an article in "
British Plastics & Rubber" (10/06/2009 – also see below), the claim of "harmless self-destruction" needs substantiation.
2
Why buy an expensive cloth bag when your free plastic bag can be used many times over - it will fit in your pocket or handbag.
Quite. And there's a lot to be said for the fact that plastic bags need very little space and energy. But experience shows that most consumers do not reuse their free plastic bags; at best they use them as bin liners once they've carried their shopping home. And the argument of "automatic" degradability may encourage people to litter even more (again, see the article cited in 1, above, and cited in full below).
Again, we as consumers need to change our habits…
3
Plastic is made from a by-product of oil-refining which used to be wasted, so nobody is importing extra oil to make it.
The by-product is naphtha, but plastics production drives oil imports. _____________
4
The space occupied in landfills by plastic shopping bags is tiny. If we are worried about space in landfills we should concentrate on material such as builder's waste, which occupies a lot of space.
Totally agree. Builder's waste needs sorting out. Waste needs sorting out, period. The landfill culture in this country needs to transform itself into a waste-incineration culture so that _______________
The issue that Michael Stephen's comment does not address is the need to reduce the use of any kind of plastic – period.
***
British Plastics & Rubber, the "Monthly Magazine for Britain's Polymer Processors"
Oxo-degradation "bad for plastics recycling"
June 10, 2009
Two trade associations have called for restraint in the use of degradation additives in plastics, and warn that their use could lead to a valuable resource being lost. US-based NAPCOR (The National Association for PET Container Resources) is concerned that there is no publicly available data to substantiate some claims made about degradability of PET. Its chairman Tom Busard said "We urge manufacturers of PET resin and packaging to refrain from introductions of degradable additive-containing products until data is made available for review and verification so we can better understand these products and their potential ramifications". And EuPR, the European Plastics Recyclers Association, has taken issue about claims made for oxo-degradable additives and called for "industry to be watchful not to destroy the achievements of the past years in plastics recycling by using unsustainable technologies for plastics."
NAPCOR's specific concerns are that no data has been made publicly available to substantiate or document:
the claims of degradability of PET polymer containing degradable additives;
the effect of degradable additives on the quality of the PET recycling stream;
the impacts of degradable additives on the products made from recycled PET; and
the true impact on the service life of these products.
The organisation points out that the value of recycled materials, such as PET, is an important economic driver for kerbside recycling programmes. But that without the testing and data necessary to understand the potential impacts of degradable additives in PET, the whole PET recycling system could be at risk. According to NAPCOR executive director Dennis Sabourin: "We don't yet understand the impacts that these additives could have on the quality of the PET recycling stream, let alone the impacts on the safety and functionality over time of next-use PET products like recycled-content PET packaging, carpeting, or strapping."
Aside from the potential impacts on recycling, NAPCOR questions the value of the concept itself: whether or not it's proven that packaging will safely degrade in landfills, or as roadside or marine litter, the value of the inherent energy used in the manufacture of plastic packaging is lost, not recaptured as it is through recycling and re-manufacturing.
The EuPR compares plastics with an energy bank. It points out that once the energy is stored by polymerisation, it can be transformed into stable products and, depending on the product cycle, the waste produced can be mechanically recycled or its energy recovered. "In both cases the plastic has an energy value."
But it says the use of oxo-degradable additives will destroy the stored energy of the material. "It is an economic and environmental nonsense to destroy this value. Moreover, it is the most unsustainable - together with landfill - way to use the valuable oil transformed in plastic. The claim that greenhouses gases are being saved by the use of oxo-degradable additives is not a proven fact."
EuPR is also concerned about the wider effects of introducing degradation additives into the recycling stream and says that the joint efforts made by all the stakeholders in order to achieve the European recycling targets is currently at risk. "The oxo-degradable additives will jeopardise mechanical recycling as they will pollute the existing waste streams. As a matter of fact, the consumer will not differentiate the different type of plastics and will throw everything in the same bin."
The belief that oxo-degradation will relieve the problem of plastics litter is also addressed by both organisations. "Even if a package were to disappear or fragment – and we've not yet seen this evidence – it would not make the package sustainable, nor does it provide any positive impacts in terms of greenhouse gas emissions or resource conservation," said NAPCOR's Dennis Sabourin. While EuPR suggests that public attention will be diverted from recycling by thinking, "it will degrade by itself", which could actually increase littering as people would be less inclined to put their waste in litter bins.
*****
Life cycle study shows biodegradable plastics least efficient in rubbish bags
September 4, 2009
Rubbish bags made from conventional polyolefins are more eco-friendly than bags made from biodegradable plastics, and bags incorporating post-consumer reclaim are the most eco-friendly of all, according to a study from the German Association for Plastics Packaging and Films, the IK. The association has published a life cycle analysis carried out by the Institute for Energy and Environmental Research (IFEU) in Germany on behalf of a group of German manufacturers and distributors of waste bags.
The study compared bags sold in Germany and France which had been produced in China and Poland. The polyethylene bags were made from combinations of HDPE, LDPE, LLDPE, post consumer PE recyclate and chalk filler and the biodegradable bags were made from BIOP's Biopar potato starch-sourced co-polyester, from Biopar containing BASF's Ecoflex biodegradable polyester, and from BASF's Ecovio, a blend of Ecoflex and PLA – which BASF recommends only for compostable bags and not general refuse bags.
Transportation from Asia added to the environmental cost for the Chinese bags, but aside from this the IFEU found that conversion to bags and transport to point of sale were significantly less relevant in the life cycle cost equation than the raw material production.
The study was carried out using Umberto, a software product described as the standard for mass flow modelling and LCA. The assessment of affects on climate change, fossil resources, environmental damage, use of natural resources and non-renewable and primary energy showed that standard virgin PE bags had a lower environmental impact on all counts than the Biopar bags. And bags with PCR content and chalk filler had the lowest impact of all, partly because of the replacement of virgin PE content by the filler.
The report concludes "provided that PCR content does not increase the weight of the bags considerably waste bags with PCR content are a recommendable option for bag producers and retailers" and that "the scenarios of currently existing biobags show larger environmental pollution indicator results than those of polyolefin bags."
There is a lot of potential for environmental improvement of biodegradable bags, says the report, but only a combination of options (material, design and technical improvements) would bring the environmental impact profiles of biobags within range of those of the polyethylene bags.
Download a summary of
the report.
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