Issue 03/2016

Basics
Disintegration
Disintegration is evaluated at pilot-scale by simulating a
real composting environment following ISO 16929:2013 [19].
In this case, samples in their final form [20, 21] are mixed with
fresh artificial bioresidue. Oxygen concentration, temperature
and humidity are regularly controlled. After 12 weeks, the
resulting composts are sieved and the remaining amount of
material in pieces > 2 mm, if any, is determined. Photographs
are taken in order to follow the physical disappearance of
materials (fig. 4).
Pass level to be considered disintegrable under composting
conditions is > 90 % in ≤ 2 mm. If this pass level is achieved
a physico-chemical characterization of resulting composts
(blank and with sample) is conducted in order to determine
that the quality of the compost is not affected. Parameters
such as: total dry solids, volatile solids, pH, ammonium
nitrogen (N-NH 4
), nitrite nitrogen (N-NO 2
), nitrate nitrogen
(N-NO 3
), total nitrogen (N), phosphorus (P), potassium (K),
magnesium (Mg), salt content, density, and maturity level
(Rottegrad) are determined.
Ecotoxicity:
Ecotoxicity of the resulting compost is evaluated in plants
following OECD 208 (2006) [22]. For this purpose, material
in powder is added to the bioreactor with fresh bioresidue
following the same procedure than in the disintegration test
[23]. A comparison is made with the compost resulting from
blank bioreactors and bioreactors containing the material
tested with regards to plant seedling emergence and growth.
Both parameters should be higher than 90 % with respect
to the blank compost to pass the test. Two different species
are evaluated such as garden cress (Lepidium sativum) and
summer barley (Hordeum vulgare).
Finally, in order to fulfill the requirements stated in the
European Parliament and Council Directive 94/62/EC on
packaging and packaging waste, an end-of-life option has to
be selected before placing a packaging product in the market.
Composting is one of the diverse recovery options available
to reduce and recycle packaging waste. However, because
of the increasing number of new compostable materials in
the market and in development, it is necessary to certify that
these new products are compostable following standardized
testing methods and identifying them with well-recognized
logos promoted by several well-positioned entities. This will
also help final consumers to properly manage packaging
when it achieves its end-of-life and becomes waste.
www.itene.com
References and Remarks
[1] Thielen, M.: Bioplastics: Basics. Applications. Markets, Polymedia
Publisher GmbH, 2012
[2] Mensitieri, G., Di Maio, E., Buonocore, G. G., Nedi, I., Oliviero, M.,
Sansone, L., and Iannace, S. 2011. Processing and shelf life issues
of selected food packaging materials and structures from renewable
resources. Trends in Food Science & Technology, 22(2–3), 72-80.
[3] Queiroz, A. U. B., and Collares-Queiroz, F. P. 2009. Innovation and
industrial trends in bioplastics. Polymer Reviews, 49(2), 65-78.
[4] Balaguer, M. P. 2015. Doctoral Thesis. Development of active
bioplastics based on wheat proteins and natural antimicrobials for food
packaging applications.
[5] EN 13432. Packaging. Requirements for packaging recoverable
through composting and biodegradation. Test scheme and evaluation
criteria for the final acceptance of packaging.
[6] http://www.packworld.com/sustainability/green-marketing-ampclaims/ftc-cracks-down-biodegradable-marketing-claims
[7] VINÇOTTE: http://www.okcompost.be/data/pdf-document/okc-labe.pdf
[8] DIN-CERTCO: http://www.dincertco.de/media/dincertco/dokumente_1/
verzeichnisse/FirstSpirit_14406522318292015-08-26_Liste_
Prueflaboratorien_List_of_testing_laboratories_BAW.pdf
[9] ASTM D 6400. Standard Specification for Labeling of Plastics Designed
to be Aerobically Composted in Municipal or Industrial Facilities
[10] ISO 18606. Packaging and the environment - Organic recycling.
[11] ISO 17088. Specifications for compostable plastics.
[12] EN 14995. Plastics. Evaluation of the compostability. Program of
testing and specification
[13] Co is only needed for Canadian certification.
[14] Taking into account a material similar to PLA, 3 months could be
enough.
[15] Does not follow EN 13432, but it is accepted for certification in some
specific cases.
[16] ISO 14855-1:2012. Determination of the ultimate aerobic
biodegradability of plastic materials under controlled composting
conditions - Method by analysis of evolved carbon dioxide - Part 1:
General method.
[17] Constituents which are present at the concentrations of less than 1%
do not need to demonstrate biodegradability. However, the sum of such
constituents shall not exceed 5%.
[18] Also 90% with respect to a reference (cellulose) is considered as valid.
However, the sum of such constituents shall not exceed 5%.
[19] ISO 16929:2013. Plastics - Determination of the degree of
disintegration of plastic materials under defined composting conditions
in a pilot-scale test.
[29] Large materials are reduced in pieces of 5 cm x 5 cm or 10 cm x 10 cm
for films.
[21] For products and materials that are made in several thicknesses only
the thickest need to be tested.
[22] OECD 208 (2006). Terrestrial Plant Test: Seedling Emergence and
Seedling Growth Test.
[23] The compost that has to be used for this test is produced at the same
time that disintegration tests are performed.
Figure 5. Climatic chamber with photoperiod used for the evaluation
of ecotoxic effects in plants.
Figure 4. Disintegration of a sample under simulated composting
conditions in a pilot-scale test.
44 bioplastics MAGAZINE [03/16] Vol. 11