Biodegradable materials

Biological recycling of materials and products is a possibility for decreasing amounts and recycling of waste.
EU requirements

In the packaging/package waste directive (94/62/EG), requirements for recyclable packages are defined and biological recycling is one of the acceptable methods. By using biological treatment techniques according to EN 13432, the respective goals in the European Parliament and the Council’s directive 94/62/EG can be fulfilled.

Laws that forbid land filling of combustible waste (since 2003) and organic waste (since 2005) also have increased the interest for more usage of biodegradable and/or compostable materials.

Biodegradability

A test for biodegradability aims to show that materials or products like for instance plastic film, bags, forks or packages are biodegraded during a specified time and to a high percentage. The biodegradation is performed by microorganisms in either water or in soil/compost.

Biodegradable materials are investigated for degree of degradation, rate of degradation and other effects of the products on the environment (see paragraph 2 below).

Test program

A complete test program for compostabiltity according to EN 13432 therefore consists of four parts:

  1. The first step consists of characterisation of the material. Components that are potentially dangerous to the environment or important for the biological treatment are analysed; for example heavy metals, carbon/hydrogen/nitrogen contents and identification of polymers and additives.
  2. Step two constitutes a test for the ultimate degree of biodegradability of the material during optimal conditions according to one of the following methods in which the amount of carbon dioxide produced is measured:
    - aerobic (with oxygen) aquatic biodegradation according to eg. ISO 14852,
    - aerobic small scale composting according to eg. ISO 14855.
    The biodegradability tests can be completed with determinations of biomass and carbon balance.
  3. Step three is a disintegration test. A control is made to ensure that the material/product is disintegrated into small fragments not possible to sieve through a 2 mm sieve. Industrially compostable waste is tested according to ISO 20200 or ISO 16929. Small scale (home) compostable waste is tested according to SP method 4148.
  4. In step four the compost derived from the disintegration test is composted to maturity. After that, its effect on water- or soil-living organisms is analysed in ecotoxicological tests. The tests can be performed on higher plants according to OECD guideline 208 + annex E in EN 13432.

Of course it is fully possible to test according to only parts of this test program. Analysis of toxic compounds is performed by Chemical Analysis. 

Certification systems

Today some certification systems for industrially compostable plastics exist in different countries. These different systems mainly contain the same test methods and criteria but use different certification labels. SP has developed its´ own certification system that in addition also includes other types of waste treatment.

Accredited laboratory

SP is also a certified and accredited laboratory for tests for the German certification system for compostable materials, DIN CERTCO.

SP actively takes part in the international standardisation work and “inter-laboratory” tests. Within an international agreement, SP´s reports are accepted in this area in Europe, USA and Japan.

Certification rules

Read more about the certification rules under the link to the right on this page.

 

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