Industrial Compostability

An overview of the different standards on specifications for industrial compostability is given in Table 5.2. Overall, there is a large similarity between these various norms. Differences are relatively small and mostly limited to minor details. 

2) Biodegradation As explained above, biodegradation is the complete breakdown to mineral end prodncts (CO2, H2O) and biomass. EN 13432 specifies it is preferably determined by ISO 14855, while alternatively other suitable international standards snch as ISO 14851 or 14852 may be used. The pass level is 90% biodegradation in absolute terms or in relative terms compared with the positive reference, cellnlose, to be reached within a maximum period of 6 months. Constituents below 1 % don t have to be evaluated as long as the total of these irrelevant constitnents is below 5%. In addition, natural materials which are not chemically modified do not have to be evaluated for biodegradation. 

ISO 17088 is similar to EN 13432 with regard to biodegradation requirements. The new ISO DIS 18066 specifies that constituents between 1 and 10% must be separately tested for biodegradation. 

ASTM D6400 allows the use of ASTM D5338 as well as ISO 16929 for determining disintegration, although this possibility is expected to be withdrawn in the near future at the next revision of ASTM D6400. 

ISO 17088 mentions ISO 14855 and ISO 20200 as alternative methods besides ISO 16929. The new ISO DIS 18066 only allows ISO 20200 as an alternative, although ISO 16929 is the preferred method. 

---

Despite its similarity to Ecoflex E, the new Ecoflex ES also shows significant differences that make it the material of choice for certain applications. One of these basic properties of Ecoflex ES is a significantly increased rate of biodegradation. This improves compostability in industrial composting facilities. 

PLA is a compostable plastic material. Chemical hydrolysis is considered to be the main degradation route for PLA [14]. This hydrolysis process takes place at high humidity and at elevated temperatures (for example in industrial composting facilities). The fragments that result from the hydrolysis process, i.e., short oligomers and monomers, then can be metabolized by microorganisms. Therefore,... 

All grades of Ecovio FS show significantly increased rates of biodegradability because they are compounds based on Ecoflex FS. This leads to improved performance in industrial composting processes. 

In November 2004, Treofan introduced labels made from Biophan for beverages and consumer products. The Biophan labels can be used in combination with bottles produced by NatureWorks PLA so that the labels may be composted together with the bottle in an industrial composting plant. 

Solid or water soluble polymers likely to enter anaerobic digestion plants or landfill site Solid polymers likely to enter anaerobic digestion plants or landfill site Solid or water soluble polymers likely to enter purification plants (PVA, for example) Polymers destined for landfill (agricultural films, for example) Polymers whose end of life is in an industrial composting facility (packaging, for example)... 

This was demonstrated by certificates of various PHA producers for industrial composting and also home composting, as well as in soil, fresh water, and marine seawater conditions. Furthermore, the complete biodegradation profile is often faster than for other biopolymers [11],... 

Nevertheless, field trials in natural environments are still used to extrapolate results acquired in laboratory tests to biodegradation behaviour under realistic outdoor conditions " Recent German regulations for the assessment of compostability of plastics even impose exposure of the product to a full scale industrial composting process to ensure that total disintegration will occur in real-life waste-processing". ... 

It is not possible to provide a specific timescale in a general standard for oxo-biodegradable polymers, (as distinct from a standard for industrial composting) because the conditions found in industrial composting are specific and the conditions foimd in the open environment are variable. Also, the time taken for oxo-biodegradable plastic to commence and complete the processes of degradation and biodegradation can be varied. 

The ASTM D6400 standard establishes the requirements for the labelling of materials and products, including packaging made from plastics, as compostable in municipal and industrial composting facihties . 

Practical test of compostability in a semi-industrial (or industrial) composting facility No negative influence on the composting process is permitted. 

---