This article has been provided by the non-profit organisation World Centric you can find them at www.worldcentric.org
Bioplastics are a new generation of biodegradable & compostable plastics, derived from renewable raw materials such as starch (e.g. corn, potato, tapioca etc), cellulose, soy protein, lactic acid etc., not hazardous in production and decompose back to carbon dioxide, water, biomass etc. in the environment when discarded. Corn starch is currently the main raw material being used in the manufacture of bioplastic resins. Mater-Bi (main component corn-starch), and Polylactide (PLA) (made from corn-starch as well) are currently the 2 main resins (raw materials), being used today in the production of compostable & biodegradable plastics and are certified for compostability under standards set by international organizations. However, other resins are coming into the market made from potato starch, soybean protein, cellulose etc. Most of these are currently not certified for compostability, though some are for biodegradability. The field of bioplastics is constantly evolving with new materials and technologies being worked on and being brought to market.
Corn-starch based products (bags, corn cutlery, cold cups, drinking straws) - 120 degrees F
Potato and tapioca starch based products (potato cutlery) - 220 degrees F
Biodegradability & Compostability
Bioplastics can take different length of times to totally compost, based on the material and are meant to be composted in a commercial composting facility, where higher composting temperatures can be reached and is between 90-180 days. Most existing international standards require biodegradation of 60% within 180 days along with certain other criteria for the resin or product to be called compostable. It is also important to make the distinction between degradable vs. biodegradable vs. compostable as often these terms are used interchangeably.
There are currently few international organizations which have established standards and testing methods for compostability, namely:
The ASTM, CEN and DIN standards specify the criteria for biodegradation, disintegration and eco-toxicity for a plastic to be called compostable.
In the USA, the BPI ( Biodegradable Products Institute ) certifies bioplastics under the ASTM
ASTM-6400-99 , standard for "compostable plastics" and awards their logo to products which pass this certification.