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Question : Does d2w™ comply with ASTM 6400 and EN13432?
Answer :
International Standards for compostability, (e.g. EN 13432 and ASTM D 6400) require that the carbon in the polymer is “completely consumed” during the composting process. That is - converted to carbon dioxide, minerals and a small amount of dead-cell biomass in 180 days or less. However this is not the way in which nature converts its waste to valuable fertilisers.
It is important to recognise that compost is an artificial man-devised process. Although composting involves biodegradation it is quite different from biodegradation in the natural environment. By contrast, tests for compostability are designed to satisfy the requirements of manufacturers of bio-based plastics.
European standard EN 13432 applies to composting of plastic packaging, but it is not appropriate for testing oxo-biodegradable plastics. This is because it is based on measuring the emission of carbon dioxide during degradation. Hydro-biodegradable plastic is compliant with EN 13432, precisely because it emits CO2 (a greenhouse gas) at a high rate.
If a leaf were subjected to the CO2 emission tests included in EN13432 it would not be considered biodegradable or compostable!
Another problem with EN 13432 is that it requires almost complete conversion of the carbon in the plastic to CO2, thus depriving the resulting compost of carbon, which is needed for plant growth, and wasting it by emission to atmosphere.
Conversion of organic materials to CO2 at a rapid rate during the composting process is not “recovery” as required by the European Directive on Packaging and Packaging Waste (94/62/EC as amended), and should not really be part of a standard for composting. Nature’s lignocellulosic wastes do not behave in this way, and if they did the products would have little value as soil improvers and fertilisers, having lost most of their carbon.
EN 13432, does not however require that plastics biodegrade during and after composting within any particular time-scale. Paragraph 5 of EN 13432 says: "It is important to recognise that it is not necessary that biodegradation of packaging material or packaging be fully completed by the end of biological treatment in technical plants but that it can subsequently be completed during the use of the compost produced".
This is what oxo-biodegradable plastic does, and it is consistent with the behaviour of nature\\'s waste products such as twigs, leaves and straw, which take years to biodegrade fully. Oxo-biodegradable plastics will biodegrade much more quickly.
The EU Directive does NOT require that when a packaging product is marketed as “degradable” or “compostable” conformity with the Directive must be assessed by reference to EN13432. In the first place although the Directive provides that conformity with its essential requirements may be presumed if EN 13432 is complied with, it does not exclude proof of conformity by other evidence, such as a report from a reputable testing institution. Indeed Annex Z of EN13432 itself says that it provides only one means of conforming with the essential requirements.
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