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Opinion Single-use

Opinion Single-use carrier bags Littering, legal banning and biodegradation in sea water. By Francesco Degli Innocenti Ecology of Products and Environmental Communication Novamont S.p.A. Novara, Italy Single-use carrier bags are a shining example of overpackaging all around the world. Needless to say, the thin, single-use carrier bags have a bad reputation, and mostly based on fact! The first problem is that they are generally used just once, which is a waste of resources and can become a litter problem. Carrier bags are always the highest-ranking in the ‘top 10’ marine litter items as reported in the UNEP Report ‘Marine Litter: A Global Challenge’ [1]. However, to be fair we should mention that single-use carrier bags are also frequently reused as waste bags for garbage collection. In this case they play a positive role because they help in reducing the consumption of resources, by substituting waste bags (a waste bag is not produced whenever a carrier bag is used instead; this is called ‘avoided impact’ in Life Cycle Assessment). The problem is that, whenever bio-waste separate collection is in place (and this is an unrelenting trend), the use of plastic carrier-bags is negative, because they are not biodegradable. The organic recycling of biowaste requires plastic-free streams to assure high recycling rates. The plastic carrier bags are not ‘multi-purpose’ waste bags. The last important consideration is that for most packaging any reduction is difficult to achieve because this usually implies negative consequences on the shelf-life of the food. On the contrary, single-use carrier bags can be substituted, without negative effects on the consumer and on retailers, by a more sustainable solution: the durable reusable carrier bag. All these factors have generated a series of initiatives to reduce the consumption of single-use carrier bags. Many retailers, committed to reducing the environmental impact of their businesses, have tried to shift towards more sustainable solutions. Also specific legislation has been developed in some countries to force this shift in consumption habits and some legislation has already been announced. In particular, some months ago, UK Prime Minister David Cameron warned supermarkets that unless stores deliver ‘significant’ reductions in the use of single-use bags over the next 12 months, they could either be banned outright from giving them away or be legally required to charge customers for them. In Italy a ban on the commercialisation of plastic 44 bioplastics MAGAZINE [04/12] Vol. 7

Opinion bags has been already in force since January 2011. The Italian ban on single-use carrier bags can be considered as an interesting experiment, the results and implications of which should be fully assessed. The first lesson is that consumers are ready to change their habits quickly to adopt more sustainable behaviour following legislation promoting packaging reduction. A study has shown that the use of single-use carrier bags has dropped significantly (50%) after the enforcement of the ban [2]. According to a survey conducted by ISPO [3] the reduction of single-use plastic carrier bags was of about 20%. These, and other statistics that will very likely be prepared in the future, show that prevention, the top priority in European waste policy, has been easily achieved with apparently no big distress to the consumer. The implicit consequence is: the lower the amount of single-use carrier bags in circulation, the lower the risk of littering. Therefore, restriction to single-use carrier bags helps efficient use of resources, waste prevention, and litter prevention. Less resources are consumed, less waste needs to be recovered and less pollution is produced. Only biodegradable and compostable [4] single-use carrier bags can still be sold by the Italian retailers when, for instance, the consumer has forgotten to bring a reusable bag. The use of biodegradable and compostable singleuse carrier bags is having very interesting consequences. The relative increase of biodegradable and compostable carrier bag volumes has resulted in the promotion of a new industrial chain and fostered innovation and development of the bio-economy while new ventures have been immediately announced by important international companies. There have also been improvements in bio-waste collection and recycling [5]. Biodegradable and compostable carrier bags can be re-used as ‘multi-purpose’ waste bags, allowing secondary use, and are suitable both for residual waste (any waste that cannot be collected in a separate way), as well as for bio-waste (e.g. kitchen waste). This is usually well communicated to the consumers by slogans such as: ‘use and re-use for the separate collection of waste’ and others, printed on the bags which become a vehicle for education. The risk that a non-biodegradable bag is improperly used to collect bio-waste is cancelled out if the householder is supplied with only biodegradable and compostable bags. This in turn improves the quality of biological recycling and relevant environmental benefits. A plastic-free compost maintains fertility of soils, where bioplastics originate, in a virtuous ‘cradle-to-cradle’ (or, strictly speaking, soil-to-soil) loop. All this is possible thanks to another Italian law that allows only certified biodegradable and compostable waste bags for the separate collection of bio-waste. This has turned out to be an interesting example of support for the bio-economy. Innovation needs a proper ‘landscape’, namely framework conditions that favour the development of the industrial/commercial process. State aid is not necessarily needed, but rather smart, sustainable, and inclusive legislation that finds comprehensive solutions for different problems. But what if the biodegradable and compostable carrier bags, in spite of all the communication that accompanies it, are littered into the environment? Recent developments in the sector of biodegradation research show that suitable carrier bags that reach the sea are effectively susceptible to biodegradation [6]. But this should not be misunderstood: the biodegradability of products cannot be considered as an excuse to spread waste that should be recovered and recycled. Human population and the current levels of consumption - and consequently of waste production - are huge. The environmental burden of littering is unbearable, even for biodegradable products. Sewage that is composed of biodegradable substances must be treated in a wastewater treatment plant before discharge into the sea or a river. The same applies for EN 13432 biodegradable and compostable carrier bags. [1] [2] Italian Ministry of the Environment: Analisi di Impatto della Regolamentazione (A.I.R.) (Regulatory Impact Analysis). [3] “I nuovi bio-shopper - Indagine su conoscenza e valutazione dei nuovi bio-shopper tra la popolazione italiana”, 2° edizione (23-25 January 2012). [4] According to the European harmonised standard EN 13432 [5] Massimo_Centemero_-conf-Stampa-12.01.2012-DEF.pdf [6] Tosin M, Weber M, Siotto M, Lott C and Degli-Innocenti F (2012). Laboratory test methods to determine the degradation of plastics in marine environmental conditions. Front. Microbio. 3:225. doi: 10.3389/ fmicb.2012.00225 bioplastics MAGAZINE [04/12] Vol. 7 45

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