Basics BIOBASED > - 85 %
Basics BIOBASED > - 85 % - 50 % BIOBASED 50 BIOBASED 20 85 % Fig. 3: The DIN CERTCO quality logo for biobased products [6] when investigating lubricants an exact definition of mineral (fossil) and biogenic lubricants can be achieved, with cosmetics the differentiation between mineral and biological ingredients is often difficult. In all cases, by analysing the 14 C content, conclusions can be drawn about the actual level of renewable (i.e. biological) ingredients. The determination of the level of biogenic materials in bioplastics is also based on analysis of the biogenic carbon level. A common method here is as in the ASTM-D6866 standard [4], which is based on the same principle as radiocarbon dating without attempting to identify the age of the specimen and using the method aimed at measuring the biobased content of the materials [4] . In addition to the redrafting of the German packaging ordinance, which since 2005 has exempted certified compostable biopolymers that contain at least 75% renewable resources from the obligation to be accepted for return by the suppliers, in the recent past special regulations covering bioplastic have been increasing. In the future therefore, there will be more attention paid to the percentage of renewable resources used [5], which currently can be most accurately checked using the above standard. A weak point in the procedure lies in the fact that it supplies only data on the biogenic carbons without considering other substances such as hydrogen, oxygen or nitrogen. Thus a bioplastic filled with glass fibres qualifies as 100% biobased, as only the biobased carbon content is identified. Anorganic fillers of natural origin on the other hand (e.g. calcium carbonate) are classified as non-biobased materials since calcium carbonate contains no 14 C [5]. A further difficulty is found in the evaluation of bioplastic blends. This is due these days to the often very different carbon content of the components of the blend, so that in most cases it is not possible to make statements about the mass or weight percentage of renewable resources in the material directly from the biobased carbon content. Using correction factors that are obtained from the carbon content of the individual materials, and using the empirical formula, it is a simple task to carry out the calculations, and so with little expense the actual mass of biogenic materials can be easily calculated. For a comparison of a fully or partially biobased biopolymer this correction factor should always be considered when evaluating the 14 C measurement in order to ensure a genuine analogy of the values. Only in this way can, for example, a comparable value for CO 2 neutrality levels be achieved, because – to stay with the example of starch and PP – when burning PP, because of its structure, more CO 2 is produced than by starch. Figure 2 shows the total carbon content and a comparison of biobased with non-biobased carbon of a few examples of biopolymers according to 14 C analysis. Fig. 4: The Vinçotte certification logo for biobased products [10] Certification of the biogenic material content In parallel to establishing the method of measurement the special regulations regarding biobased plastics are constantly growing. This means that the materials or products made from renewable resources 52 bioplastics MAGAZINE [02/12] Vol. 7
are being increasingly tested for their content of biogenetic material and are also being appropriately certified. So far, in Europe, this has been possible through only with two certification offices, namely DIN CERTCO (Germany) and Vinçotte (Belgium). With both companies the 14 C analysis method presented here for checking the percentage of biogenic material is in line with ASTM 6866 and indicates on the certification logo the level of biobased carbon [6, 7]. DIN CERTCO supplies so-called ‘Quality logos for biobased products’, at various levels: 20-50%, 50-85%, > 85%, whereby the figure used relates to the biobased carbon content [6]. DIN CERTCO applies a double minimum standard in the certification procedure of each product. This is, on the one hand, a minimum level of organic material which is determined by loss on ignition, and which must not be less than 50%, as well as a minimum content of biobased carbon that must be more than 20%. If this latter figure is not reached a statement is supplied confirming the biogenic carbon content, and a ‘registration of a biobased product’ with a biobased content of < 20% (without the certification logo, symbol, or label) is issued [6, 8]. Vinçotte also gives permission to use its certification logo stating the level of biogenic carbon in the product. The crucial figure is indicated by the number of stars on the left-hand side of the logo. The levels are: 20 – 40% (1 star), 40 – 60% (2 stars), 60 – 80% (3 stars) and > 80% (4 stars). Again the percentage figure used indicates the biobased carbon level of the material [7, 9]. With both of these programmes only a voluntary certification is offered which the manufacturer may or may not wish to request. A unified guideline for the testing and certification of biobased products, as well as a unified evaluation of the materials, is currently planned at a national and international level, but has not yet been presented [11]. Additionally, at the current time the option is being discussed of using not only the ratio of the carbon isotopes to determine the biobased content, but also to use the isotope ratio of other elements such as oxygen, nitrogen and hydrogen. However a new standard must first be developed [11]. Gesamt-Kohlenstoffanteil [%] 100 90 80 70 60 50 40 30 20 10 0 PVLA PHB PLA PLA-Copolyester-Blend PBS biobased not biobased Fig. 2: Percentages of biobased and non-biobased carbon content within the total carbon content of various bioplastic molecules Copolyester References [1] S. Bowman, Radiocarbon dating, University of Carlifornia Press, 1990. [2] L. A. Currie, The remarkable metrological history of radiocarbon dating (II), Bd. Journal of Research of the National Institute of Standards and Technology, Gaithersburg, U.S.A.: National Institute of Standards and Technology, 2004. [3] TÜV Rheinland, 2011. [Online 2011] http://www.agroisolab.de/de/unterscheidung_biogen_fossil.html [4] ASTM-D6866-04, Standard Test Methods for determing the biobased Content of natural range Materials using radiocarbon and isotope radio mass spectrometry analysis, West Conshohocken, United States: ASTM International, 2004. [5] Endres, Hans-Josef; Siebert-Raths, Andrea, Technische Biopolymere, München: Carl Hanser Verlag, 2009. [6] DIN CERTCO, „Zertifizierungsprogramm biobasierter Produkte nach ASTM 6866,“ November 2010. [Online 2011] www.dincertco.de [7] Vincotte, „Certification - C14 Dating Method,“ 2011. [Online 2011] http://www.okcompost.be, Dokumentation [8] DIN CERTCO, [Online 2011] www.dincertco.de [9] Vincotte, „Zertifizierung - OK biobased und Gebrauch der Logos,“ 2011. [Online 2011] http://www.okcompost.be, Dokumentation [10] Vincotte, [Online 2011] http://www.okcompost.be [11] DIN CERTCO, „Zertifizierung von biobasierten Produkten,“ November 2010. [Online2011] http://www.dincertco.de [12] B. Kromer, „Bestimmung des fossilen Kohlenstoffanteils mit 14C,“ Heidelberger Akademie der Wissenschaften, Heidelberg, 2009. [13] P. Becker-Heidmann, Die Tiefenfunktionen der natürlichen Kohlenstoff-Isotopengehalten von vollständige dünnschichtweise beprobten Parabraunerden und ihre Relation zur Dynamik der organschen Substanz in diesen Böden; Dissertation, Hamburg: Hamburger Budenkundliche Arbeiten, 1989. [14] W. T. Hering, Angewandte Kernphysik: Einführung und Übersicht, Stuttgart, Leipzig: Teubner Verlag, 1999. [15] Universität Erlangen, [Online 2011] http://www.14c.uni-erlangen.de [16] Beta Analytic Inc., „Explanation of results - biobased Analyses unsing ASTM-D6866-11,“ Miami, 2011. CA-Blend Celluloseester Bio-PE Starch - PP - Blend bioplastics MAGAZINE [02/12] Vol. 7 53
