Traditionally plastics ( “GEN 1 ” ) have been derived for the most part from fossil fuels, be it natural gas or the naptha portion of a barrel of oil.  Truly biodegradable plastics ( GEN 2″ ) must be derived from agricultural sources.  Despite the recent tipping point of plastic bashing, they have not caught on simply because of timing and cost.  It’s very simple.  If you don’t know when the plastic is going to break down, it makes no sense to put mass quantities in bulk rail cars.  The plastic would degrade long before it gets to the processor. 

The approach of “OXY” biodegradables is to add something to weaken the polymer chains thereby hastening their degradation.  Whether or not this leads to true BIOdegradation is up for grabs.  

We are at the juncture “GEN 3” plastic.

You might want to take a quick look at how biodegradables can play out. 

Meantime, the gulf coast of the US is poised to add an additional 20 billion pounds annual capacity of polyethylene by 2022.  That’s just polyethylene and does not include another 10 billion pounds of grass roots plants in PA, OK and Alberta, Canada.   The senior product managers of resin companies all agree that’s probably not enough to satisfy world demand.  There is a lot of polypropylene capacity coming on too.  Braskem who marketed their “green” PE and PP derived from sugar cane is adding a billion pound annual capacity plant in La Porte, TX to make conventional polypropylene from fracked fossil fuels, not sugar cane.   Ironically, their CEO praised the US feedstock situation as a major factor in the decision to locate the plant in TX instead of importing LNG derived from sugar cane.

If you identify a circumspect biodegradable claim, click here to send a complaint to the Federal Trade Commission.  They are finally paying attention and cracking down on what is known as the “additive cowboys”.  In another ironic twist, they sued an oxobiodegradable additive manufacturer the US military specifies for their field latrine bags.