Brentwood Plastics blog

Timing is crucial to biodegradable plastics

Posted by Joel Longstreth on Tue, Sep 17, 2013 @ 04:31 PM

20130917 163658 Our 4 year oxobiodegradable bag is breaking down.  The reusable bag we made from plain LDPE while George H W Bush was president is still going strong.

The folks at told us they didn't like the concept of a biodegradable reusable bag; they were more into "lifetime" bags.  

The contrast of the two projects was interesting.  The Makro bag was "outside in" thinking, or responding to a need.  The biodegradable bag was my "inside out " concept and while functional, a commercial dud.  I learned a lot, though.  Mainly how much visceral hatred there is for plastics, even if biodegradable ( " you're still usin' evil fossil fuels, MAN ! ).   I found it amusing these same people like their woven polypropylene reusable bags printed with heavy metals for the conspicuous consumption billboard.  

20130917 172812

How times have changed.  I went to the Whole Foods flagship store in Austin a few weeks ago and was denied a plastic shopping bag.  Nobody sees the irony of what must be millions of pounds of plastic that pass through Whole Foods every year in packaging.

At long last the FTC is going after biodegradable additive manufacturers who have specious claims.  The central issue ?  timing


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Topics: biodegradable plastics

Green Wash - What is Green Wash Plastics ?

Posted by Joel Longstreth on Thu, Nov 03, 2011 @ 04:25 PM

Greenwashing is ubiquitous. 

Claims of plastic biodegradability are vague and play into the public's emphasis on end-of-life.

The FTC lags in prosecuting specious claims and only prosecutes the most flagrant offenders.

So how can one make an informed decision about ostensibly eco friendly biodegradable plastic without a 3 hour course on confusing biodegradability standards ? 

ASTM D 6400, ASTM D 6954-04, ASTM D 5511, ASTM D 5526, ASTM D 7021, ISO 15985, EN 14995, EN 13432, ISO 17088 to name a few.

Compliance with specific test methods is rarely mentioned at point-of-sale.

The sad truth is there is a lot of biodegradable patent medicine being peddled these days.  Us plastic nerds have heated debates about these standards while this information doesn't usually reach the consumer.

If you don't know your PLA from your PHA or your PHB, if you don't know your oxobio from your bioplastic, here are 3 dumb questions which will make you an informed consumer:

Does it comply with at least one standard ?

Does the companies' website have one study to substantiate their claims ?

If the product claims to be compostable, is it home compostable or must it be transported to a commercial composting facility ?

If the onset of degradation is specific, such as 2 weeks after the product is used, how does the plastic know it is time to initiate degradation ?  In other words, how is the plastic so smart it knows it is no longer on the supermarket shelf ?

If the bag, usually a newspaper bag, claims a percent of POST CONSUMER content, did the plastic really get discarded, collected, sorted, returned and repelletized then made into plastic film again ?  According to the FTC and ASTM, true post consumer means made from previously used product.

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Topics: biodegradable plastics, green wash, greenwashing, what is greenwash ?, green washed

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