Editing Biopolymer (section)

===Environmental impacts===
Biopolymers can be sustainable, carbon neutral and are always [[renewable]], because they are made from plant or animal materials which can be grown indefinitely. Since these materials come from agricultural [[crops]], their use could create a [[sustainable]] industry. In contrast, the feedstocks for polymers derived from petrochemicals will eventually deplete. In addition, biopolymers have the potential to cut [[carbon emissions]] and reduce CO<sub>2</sub> quantities in the atmosphere: this is because the CO<sub>2</sub> released when they degrade can be reabsorbed by crops grown to replace them: this makes them close to [[carbon neutral]].

Almost all biopolymers are [[biodegradable]] in the natural environment: they are broken down into CO<sub>2</sub> and water by [[microorganisms]]. These biodegradable biopolymers are also [[compostable]]: they can be put into an industrial composting process and will break down by 90% within six months. Biopolymers that do this can be marked with a 'compostable' symbol, under European Standard EN 13432 (2000). Packaging marked with this symbol can be put into industrial composting processes and will break down within six months or less. An example of a compostable polymer is PLA film under 20μm thick: films which are thicker than that do not qualify as compostable, even though they are "biodegradable".<ref>[http://www.nnfcc.co.uk/publications/nnfcc-newsletter-issue-5-biopolymers-a-renewable-resource-for-the-plastics-industry NNFCC Newsletter – Issue 5. Biopolymers: A Renewable Resource for the Plastics Industry]</ref> In Europe there is a home composting standard and associated logo that enables consumers to identify and dispose of packaging in their compost heap.<ref name="nnfcc" />