1. Compostable plastics certification
Standards are a set of requirements which a product or service has to fulfil. There are two main groups of standards:
n standard specification, a set of requirements, pass/fail values which a product must comply with to be assigned with a certain label. An example of standard specification for compostable plastics is EN 13432. The basis of EN 13432 requirements was then broadened to plastics with standard specification EN 14995. There are also other standard specification e. g. ASTM D6400, ISO 17088 and others;
n test methods, evaluations, determinations or practices. Test methods describe how to perform tests and how to validate them. To test specific characteristic of the compostable product there is a reference in a standard specification to the relevant test method according to which testing should be carried out.
Standard specifications are most often the basis for a certification system/scheme – but not always (the certification scheme for bio-based plastics). Certificate is a confirmation that a product/service is in compliance with the specific request. The verification and testing of a product are based on test methods.
1.1. Specification for compostable plastics
The most known specification for compostability is previously mentioned EN 13432. According to this standard specification the following requirements for compostable products apply:
n content of heavy metals and other elements below the limits mentioned in the Annex A of the standard;
n disintegration analysis during biological treatment. 3 months (12 weeks) analysis in industrial or half industrial composting conditions should present sufficient disintegration level (not more than 10% of dry matter should stay above 2 mm sieve);
n Biodegradation analysis – at least 90% of the organic carbon MUST be converted into carbon dioxide within 180 days (mineralization);
n ecotoxicity analysis assessing that biological treatment is not decreasing the level of compost quality – this is determined by a plant growth test.
Composting, also called organic recycling, basically signifies oxygen processing capability of waste. This process is conducted in strict controlled conditions by microorganisms, which turn organic carbon into carbon dioxide. Product of this process is organic matter called compost.
Confirmation of positive compostability can be put into practice in a form of a certificate that can be awarded for final products. It is also possible to obtain a registration of the raw materials (polymers), intermediates and additives. Producers of materials cannot use the certification as producers of products can, but once their material is registered according to the EN 13432, producers of final products that would like to have their product certified can use this registration to avoid the testing procedure for that material, which is both expensive and time consuming (with the respect to registered thickness and the thickness of the material).
Germany was one of the first countries which started the certification of biodegradable plastics. Basics for certification criteria were prepared by Biodegradable Materials Interest Community Association (Interessengmeinschaft Biologisch Abbaubare Werkstoffe – IBAW), which in 2006 changed to European Bioplastics Association. Fig. 1. shows European certification systems and different composting marks.
In Europe main certification bodies that introduced a certification system are operated by DIN CERTCO (member of German Institute for Standardization DIN) and Vinçotte. DIN CERTCO’s system has national partners operating in Germany, Switzerland, Netherlands, Great Britain and Poland, and Vinçotte system is available internationally through its Belgium and Italian office. Italy has its own certification body for compostable plastics called CIC (Italian Composting Association together with Certiquality). Both DIN CERTCO and Vinçotte’s successful certification means that a producer can place a mark that is called the Seedling logo. The Seedling logo is owned by European Bioplastics Association and it signifies to the final consumer that a product is to be collected with other compostable organic waste. In addition to that both DIN CERTCO and Vinçotte have their own composting symbols which can be also placed on the products, based on which certification body was used for determining the compostability. CIC only awards compostable products with their own compostability label. Fig. 2. shows composting marks which are given to certificated products by DIN CERTCO, Vinçotte and CIC.
Composting capability confirmation is given under the following conditions:
1. all materials included in a product have to be compostable – unless they can be separated easily – as in the case of a yogurt cup and a lid;
2. packaging material thickness has to be lower or the same as the maximum thickness in which it has biodegraded – the registration was awarded;
3. packaging must not have any dangerous additives for the environment. Its intended use should be described in details. Certificate is not given when the product has any additives which could decrease compost quality.
In addition to the industrial compostability certifications DIN CERTCO and Vinçotte also offer additional Certification Scheme for Home Composting. Certification marks for HOME composting are shown on fig. 3. Owing to the comparatively smaller volume of waste involved, the temperature in a garden compost heap is much lower and less constant than in an industrial composting environment. This proves „garden” composting to be a more difficult, slower-paced process. OK HOME compost certification schemes guarantee complete biodegradability in garden compost heap.
Vinçotte also awards products that are biodegradable in soil and in water with a certification mark. Similarly the Soil and
Water Biodegradation certification systems guarantee that products will completely biodegrade in the soil and fresh water without adversely affecting the environment. Note that the Water Biodegradability certification does not guarantee that products will biodegrade in marine environment (salt water).
In the USA certification is based on ASTM D6400. Fig. 5. shows composting mark given by US Composting Council and Biodegradable Products Institute.
2. Bio-based content certification
Determination of the bio-based content is based on the principle of measuring the activity of the 14C isotope. Materials – both those based on fossil resources as well as those based on renewable resources – are mainly composed of carbon that can be found in three isotopes in the nature: 12C, 13C, and 14C. The 14C isotope is unstable, decays slowly and is naturally present in all living organisms. The content of 14C in all living organisms is very stable since it is related to the concentration of 14C in the environment which is close to constant. When the organism is deceased, it stops absorbing the 14C isotope from the environment. From that moment onward the 14C concentration starts to decrease due to natural decay of the isotope. The half-life of 14C is known to be around 5 700 years. This is not noticeable in the range of a human life, but within 50 000 years the content of 14C decreases to a level that cannot be measured. This means that the concentration of 14C in fossil resources is negligible.
ASTM D6866 standard using the above principle is the basis for certifying materials, intermediate products, additives and products based on renewable resources.
Both Vinçotte and DIN CERTCO introduced an evaluation system for the content of the renewable resources in a plastic material or product. In essence such certification system evaluates the proportional content of old (fossil) and new (renewable/biogenic) carbon. Fig. 6. shows the difference between the old and new carbon. Carbon age signifies a time needed to get carbon for manufacturing a product. Classical/conventional plastics are manufactured from fossil resources containing carbon produced for millions years. On the other hand, plastics manufactured from renewable crops (corn, s
ugarcane, potatoes also farm and food production waste) contain carbon which circulates in nature for maximum a few years. For wooden products carbon age is about several dozen years old.
In EU first plastics containing renewable resources certification system was introduced in Belgium by AIB-VINÇOTTE International S.A. Bio-based content certificate is available for products that contain at least 20% of renewable source carbon and is divided into four groups:
n 20-40% renewable resources content;
n 40-60% renewable resources content;
n 60-80% renewable resources content;
n over 80% renewable resources content.
This system could be used for many products completely or partly manufactured from natural origin materials/polymers/resources (except solid, liquid and gaseous fuel). Evaluation criteria that are a base for this certification are publicly available [7]. Criteria includes basic specifications. To apply for certification product has to contain at least 30% organic carbon calculated in dry matter and at least 20% organic carbon from renewable resources. Analysis is based on the ASTM D6866 [8] standard, method B or C. The certification applies only to materials which are non-toxic and are not used in medicine.
Number of the stars on the symbol signifies the percentage of renewable resources in a certain product. Fig. 7. shows symbol which confirms that product is made from renewable resources and gives an explanation of the meaning of a certain part of the certification label.
DIN CERTCO bio-based polymer certification applies for many branches and products (except of medical, petrochemical and toxic products) and one additional requirement: the content of the volatile solids must be higher than 50% mass. Passing the certification procedure permits the producer to put special symbol with the percentage of the renewable resources content on a product [9]. Certification scale has three grades:
n from 20% to 50%;
n from 50% to 85%;
n over 85% of renewable resources.
Fig. 8. displays certification marks which show the percentage of the content of the renewable resources.
When a product is consisted from more than one element then the company applying for the certificate needs to certify each element of the product separately. On the other hand it is possible to certify a group of products, provided that they are made from the same material and have similar shape and the size is the only differentiating factor.
3. Certification – summary
Fig. 9. shows how standardization and certification of bioplastics is consisted. Bioplastics are bio-based, biodegradable or both (definition of European Bioplastics). Certification schemes are separated. For bio-based plastics (plastics made from renewable resources) only test methods exist, there is no standard specification because the necessary result for certification scheme is the proportion of renewable carbon in comparison with old carbon and is a result of the measurement. Based on the result of the determination of the bio-based content the product/material is awarded with a certificate.
Biodegradable plastics are divided into:
n plastics biodegradable in water, both standard specification and test methods exist, also certification scheme is developed;
n plastics biodegradable in soil, only test methods are developed and no standard specification, certification scheme is developed;
n anaerobically biodegradable plastics, only test methods are developed, there is no standard specification and no certification scheme;
n and compostable plastics which are then divided to:
– plastics suitable for industrial composting, for this field we have the most standard specifications, standard test methods and certification schemes;
– plastics suitable for home composting, standard specification was published in 2010, developed are standard test methods and also certification schemes;
n as the last group of biodegradable plastics we can find oxo-degradable plastics, but this group does NOT actually belong to bioplastics because at this moment there is still lack of evidences that in the process of digestion occurs (involvement of microorganisms). For oxo-degradable plastics we have some test methods, but at the moment there is no standard specification and also no certification scheme.
– The field of standardization and certification of bioplastics is very broad, complex and fast changing. For more specific information contact the above mentioned certification bodies.
4. Confirmation of greenhouse gases emission reduction
Legislative restrictions on emissions of greenhouse gases influenced many evaluation methods of those emissions, counting methods that can be applied to products including packaging. Most popular method is called the carbon footprint or carbon profile. For a plastic product a carbon footprint amounts to overall directly and indirectly emitted CO2 (and other greenhouse gases) throughout its whole life cycle. In Europe most popular carbon footprint calculation is currently based on PAS 2050: 2011 [10] published by BSI (British Standards Institution). Fig. 10. shows five steps of calculation procedure. Fig. 11. on the other hand shows life cycle stages and data needed to complete a carbon footprint evaluation.
In 2007 Carbon Trust (organization financed by British government) introduced a new mark called Carbon Reduction Label – the current version of the symbol is shown on Fig. 12. Carbon Reduction Label shows overall CO2 and other greenhouse gases emission calculated as CO2 equivalent in all life cycle stages (production, transport, distribution, removal and recycling). Base for evaluation is PAS 2050: 2011 [12]. Carbon Reduction Label informs consumers about greenhouse gases emission level and helps them to make deliberated decisions that are beneficial for the environment [13].
Producers cooperating with Carbon Trust analyse process maps related to life cycle of their specific products. With understanding of the greenhouse gas emissions of their processes companies are able to change technical and logistical solutions which can then reduce this emission. Producers of the following products took part in the pilot testing of this scheme: orange juice, potato flakes, detergents, light bulbs, clothes. Fig. 13. show examples of Carbon Reduction Label on a product from a supermarket retail chain.
A major global beverage producer is another notable example of cooperation with Carbon Trust. Fig. 14. shows process tree of beverages life cycle and fig. 15. shows the breakdown of carbon footprint per production processes. As one can see for a glass bottle carbon footprint attributed to the packaging amounts to 68.5% of total CO2 emissions. For a 0.33 l metal can this value is 56.4%, a PET bottle (0.5 l) has a share of 43.2% and for a large PET bottle (2 l) amounts to 32.9% of total carbon.
Comparing carbon footprint for several beverages the highest value is for ordinary version of the beverage (1071 g CO2 per litre) in a glass bottle (0.33 l). The smallest result is for a diet version of the beverage in 2 l PET bottle (192 g CO2 per litre).
Higher values of normal version of the beverage in comparison with the diet edition of the beverage are attributed to higher sugar content, which in turn leads to increased total emissions.
References
[1] [http://en.european-bioplastics.org/].
[2] [http://www.dincertco.de].
[3] [http://www.okcompost.be].
[4] [http://www.compost.it].
[5] [http://www.bpiworld.org/].
[6] Naryan R., Biodegradability – facts and claims, COBRO 2nd CONFERENCE THE FUTURE OF BIODEGRADABLE PACKAGING, Warsaw, 29.09.2009.
[7] OK biobased: Initial acceptance tests, Vinçotte, 2009.10.01.
[8] ASTM D6866 – 2011 Standard Test Methods for Determining the Biobased Content of Solid, Liquid and Gaseous Samples Using Radiocarbon Analysis.
[9] Certification Scheme. Biobased Products in accordance with ASTM 6866 (Edition: November 2010).
[10] PAS 2050: 2011, Specification for the assessment of the life cycle greenhouse gas emission of goods and services.
[11] Guide to PAS 2050 How to assess the carbon footprint of goods and services, BSI, 2008.
[12] Tkaczyk L., Narzędzia zarządzania emisją gazów cieplarnianych, „ABC jakości” nr 3-4, 2010.
[13] [http://www.bbc.co.uk].
[14] [http://www.german-retail-blog.com/2012/04/19/tescos-carbon-footprint/].
[15] Sapiro U., Carbon foot printing and packaging, Seminar EUROPEN Beyond compliance Packaging in the Sustainability Agenda, Brussels, 26th May 2009.
[16] [http://coca-cola.co.uk/enviroment, what-s-the-carbon-footprint-of-a-coca-cola.html].
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Praca naukowa finansowana ze środków finansowych na naukę w latach 2011-2014 przyznanych na realizację projektu międzynarodowego współfinansowanego.
Scientific work financed from the funds for science in years 2011–2014 granted to implement the international co-financed project.
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PLASTiCE is a project within Central Europe programme, which started in April 2011 and will last for three years. It brings together 13 partners from 4 countries in Central Europe and is coordinated by the National Institute of Chemistry Ljubljana, Slovenia. Project focuses on identification and removal of barriers to the faster and more widespread use of sustainable types of plastics, particularly biodegradable plastics and plastics based on renewable resources, in Central Europe. PLASTiCE wants to promote new environmentally friendly, sustainable plastic solutions through complete value chain.
