Definition of biodegradable and compostable plastics and Certification Standards
In July 2000 the US Composting Council and the Biodegradable Products Institute announced certification program based on
ASTM Standard D 6400-99 for materials suitable for composting applications.

Definition of Biodegradable and Compostable Plastic:
    Degradable Plastic:
  • a degradable plastic which undergoes a significant change in its chemical structure under specific environmental
    conditions resulting in a loss of some properties. There is no requirement that the plastic has to be degrade from
    the action of "naturally occurring microorganism" or any of the other criteria required for compostable plastics.

    Biodegradable Plastic:
  • a degradable plastic in which the degradation results from the action of naturally occurring microorganisms such
    as bacteria, fungi and algae (ASTM D 6400-99)

    Compstable Plastic:
  • a plastic that undergoes degradation by biological processes during composting to yield CO2, water, inorganic
    compounds, and biomass at a rate consistent with other compostable materials and leaves no visible,
    distinguishable or toxic residue (ASTM D 6400-99)

Standards that certify biodegradable and compostable
Following international organizations have established standards and testing methods for compostability:


The ASTM, CEN and DIN standards specify the criteria for biodegradation, disintegration and eco-toxicity for a plastic to be called
compostable.  While ISO 14855 makes no stipulations regarding disintegrations or toxins remaining.

    Biodegradability: It  is determined by measuring the amount of CO2 produced over a certain time period by the
    biodegrading plastic.
  • ASTM, ISO and DIN standards require 60% biodegradation within 180 days.  
  • Europenan Norm EN13432 is the strictest standard, requirings 90% biodegradation within 90 days.

    Disintegration: It  is measured by sieving the material to determine the biodegraded size and less than 10% should
    remain on a 2mm screen for most standards.

    Eco toxicity:  It is measured by having concentrations of heavy metals below the limits set by the standards and by testing
    plant growth by mixing the compost with soil in different concentrations and comparing it with controlled compost.

ASTM Certification: In the USA, the BPI (Biodegradable Products Institute) certifies bioplastics under the ASTM 6400-99,
standard for "compostable plastics".  The certified products can display following logo.
ecoGreenwares
BPI Biodegradable and Compostable Logo