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[GreenYes] bio (?) plastic bag report


Brenda Platt at the Institute for Local Self-Reliance (_bplatt@no.address
(mailto:bplatt@no.address) ) in part writes":

Hi all,


Is anyone looking at the impact that this will have in encouraging
biodegradable plastic bags? I have been focusing most of my time the last year on
bioplastic issues and I do not support the use of biodegradable plastic bags for
shopping bags, only for collecting organics destined for composting
facilities. Biodegradable bags are not even close to being 100% biobased. Further,
all the biodegradable bags I know of are only biodegradable in commercially
operated compost facilities, not for instance, in the marine environment.


The per bag fee being proposed should apply to ALL single-use shopping bags
in order to promote reusable bags. Let's not encourage single-use
biodegradable plastic bags. BTW, the biodegradable petro-based co-polyester resin
frequently used in these bags is made by the big German chemical giant, BASF.
Let's be careful about what we are supporting. Also, coming down the pike is
biodegradable PVC products. Just because a bag is biodegradable does not mean
it is environmentally sound.


Do we care about the impact on recycling film plastics? I'd be interested
in a dialogue specifically on this issue. Biodegradable bags will become a
contaminant in film recycling. I'm no fan of petro-plastics and petro bags.
But I think this is a concern from a recycling perspective.
While I am still in the process of researching biodegradable bags, here?s
some preliminary findings by bag company.
First, a definition of biodegradability I wrote:
Biodegradable plastics are plastics that can decompose into carbon dioxide,
methane, water, inorganic compounds, or biomass via microbial assimilation
(the enzymatic action of microorganism). To be considered biodegradable, this
decomposition has to be measured by standardized tests, and take place
within a specified period time, which vary according to the ?disposal? method
chosen. The American Society of Testing and Materials (ASTM) has created
definitions on what constitutes biodegradability in various disposal environments.
Plastics that meet ASTM D6400, for instance, can be certified as
biodegradable and compostable in commercial composting facilities. In Europe the
equivalent standardized test criteria is _EN 13432_
(http://www.european-bioplastics.org/index.php?id=158) . In the US, there is a biodegradability standard
for soil (ASTM D5988), a biodegradability test standard for marine and fresh
water (ASTM D6692 and D6691), one for wastewater treatment facilities (ASTM
D5271), and one for anaerobic digestion (ASTM D 5511). Other countries have
similar standards and certifications. Belgium is unique in offering ?The OK
Compost? mark, which guarantees that the product can be composted in home
composting systems. While many bioplastics are indeed certifiable as compostable
in commercial compost facilities, not all can be home composted and not all
are biodegradable in the marine environment. Furthermore, a number of
petrochemical-based polymers are certified biodegradable and compostable.
Biodegradability is a directly linked to the chemical structure, not to the origin of
the raw materials.
Eco Film: No biobased content at all.
Eco Works: Can contain between 5-70% corn based resin (5-70% biobased
content, most collection bags are on the low end)
Mater-bi (BioBag): Blend of petro-derived polyester and starch (the starch
may or may not be from corn and the biobased content is around 20-30%,
remaining 70-80% is petro-derived)
Cereplast: Uses a blend of petroleum-based polyester, possibly some small
PLA amounts and possibly other materials. Not sure about biobasd content, but
one industry rep (not with Cereplast) told me that he believes their bags are ?
more than likely 70-100% petroleum derived.? [Cereplast also uses
nanocomposites, which I have a huge problem with. Any community embraces the
precautionary principle should not be promoting products with nanoparticles.]
Bio-Tuf/Heritage: Blend of polyester and calcium carbonate filler. Don?t
believe they claim any biobased content at all. Petro-derived polyester is
likely 85% of the formulation, but don?t know precise.
Mater-bi (BioSak); Blend of polyester and corn-based starch. They're in
the same range of biobased content (20-30% biobased. 70-80% petro-derived).
All of the above bags are certified compostable, but none are
petroleum-free. Nearly all are a vast majority petroleum-derived content.
Best,
Brenda



Brenda Platt
Institute for Local Self-Reliance
927 15th Street, NW, 4th Fl
Washington, DC 20005
tel: 202-898-1610 ext. 230
fax: 202-898-1612
_bplatt@no.address (mailto:bplatt@no.address)
_http://www.ilsr.org_ (http://www.ilsr.org/)












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