Compostable – Why

Compostable

There are different compostability and Biodegradability standards worldwide . The europen standard EN13432 -2006  is the most widely recognized standard .The American standard is ASTM D 6400 and the Australian Standard is AS4736-2006 . The compostable product should meet all the requirement of EN13432 and other standards . Compostable and biodegradable bags should completely decompose in an ideal composting environment in a given time frame and should not leave any halmful residues in the soil . 

What is Composting ?

Composting is the process of breaking down organic waste by microbial  digestion to create compost. For composting process to take place correct level of heat , water , oxygen should be available . There should be millions of small microbes consuming the waste and transform organic material into compost The term compostable means that a material is compatible with a composting process. The European standard EN 13432 has put down  the characteristics a finished product must fulfill the following to get an organic recovery. Compostable means that a material. 

  • Biodegradable under composting conditions.
  • Disintegrates completely in one composting. Cycle.
  • Should not have toxic effects and does not release heavy metals over a given value into the compost
  • Should not have negative effect on the composting process itself.

If a material is compostable it is  considered as  automatically biodegradable  and can be recovered in a composting process and the word bio degradable is used with no proper meaning attached to it. 

According to the European Standard EN 13432, a compostable material must have the following characteristics:
  • Biodegradability, which is determined by measuring the actual conversion of the compostable material into carbon dioxide. The acceptance level is 90%, which must be reached in less than 6 months.
  • Disintegrability, that is, the fragmentation and loss of visibility in the final compost . This is measured with a composting test (EN 14045). The test material is degraded, together with organic waste, for 3 months. After this time, the compost is sieved with a 2 mm sieve. The residues of test material with dimensions higher than 2 mm are considered as not having disintegrated. This fraction must be less than 10% of the initial mass.
  • Absence of negative effects on the composting process. This is checked with a composting test.
  • Low levels of heavy metals (below the predefined maximum values).
  • Each of these requirements must be met simultaneously for a material to be defined as compostable.