Miss America Gets Into the Greenwashing Game

PLA (4.00 / 1)

I love this.

PLA is a sustainable alternative to petrochemical-derived products, since the lactides from which it is ultimately produced can be derived from the fermentation of agricultural by-products such as corn starch or other carbohydrate-rich substances like maize, sugar or wheat.

PLA is more expensive than many petroleum-derived commodity plastics, but its price has been falling as production increases. The demand for corn is growing, both due to the use of corn for bioethanol and for corn-dependent commodities, including PLA.

Corn starch is an agricultural byproduct now? Hmmph.

I don't know who wrote this wiki. The article is more than a year old, last modified today. Wiki articles evolve over time, this one probably will improve eventually.

Also,

As of December 2005, NatureWorks was the primary producer of PLA (bioplastic) in the United States.

Other companies involved in PLA manufacturing are Toyota (Japan), PURAC Biomaterials (The Netherlands), Hycail (The Netherlands), Galactic (Belgium), DURECT (US) and several Chinese manufacturers. The primary producer of PDLLA is PURAC, a wholly owned subsidiary of CSM located in the Netherlands.

Galactic and Total Petrochemicals operate a joint-venture, Futerro, that is developing a second generation of polylactic acid product. This project includes the building of a PLA pilot plant of 1500 tonnes/year in Belgium.

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by: count @ Tue Sep 29, 2009 at 21:39:13 PM UTC

Bioplastics a messy subject (4.00 / 2)

Bioplastics like PLA are clearly a messy subject, but they probably have a limited role in some areas, like those urban areas with wide-spread composting (e.g., Berkeley, Oakland, San Francisco).

Education, of course, is a big issue because the PLA won't break down in backyard compost piles. But even if everyone knows that PLA can't be composted in the backyard, if they don't have access to commercial (municipal-level) composting, the material's biodegradability is not much of an advantage, given the non-reactive nature of modern landfills (where nothing breaks down or degrades).  It is definitely the exception for a city or suburb to collect green waste and carry it to a central composting facility (I wonder if anyone has created a map showing which areas have this service?).

Another problem with PLA is the confusion around the product could lead to more plastic in the stream — for example, people throwing plastic into the public compost bin because their cup looks like the cup that someone else just tossed in. When I went on a tour of the facility that composts San Francisco's green waste and food waste (my report at the Ethicurean), the biggest problem was plastic. Regulations limit how much plastic can be in finished compost, so the facility had a manual picking line with four people pulling plastic items from the raw material.  It's possible that when they see a clear PLA beverage cup, they'll pull it automatically rather than risking that is it plastic.  

Yet another issue is the poor job of labeling that I've seen from many manufacturers, as this post that I wrote for the Ethicurean indicates.

It would be interesting to see a side-by-side comparison with reusables, petro-materials, and the bioplastics. Given the energy intensity of American farming, I doubt that bioplastics will come out as much of a leader.

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by: mental_masala @ Wed Sep 30, 2009 at 04:09:17 AM UTC

I've composted PLA (0.00 / 0)

and it's worked fine.  Granted, I let my compost sit for about a year before I use it, so that might be why.

Vote for yourself at www.ni4d.us!

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by: rossl @ Wed Sep 30, 2009 at 22:27:48 PM UTC

Good point. (0.00 / 0)

What the heck is the guidance for composting PLA, anyway? Has information been published about temperature, time, etc.?

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by: count @ Thu Oct 01, 2009 at 00:44:26 AM UTC

[ Parent ]

I feel like I've read it before (4.00 / 1)

and it's mostly absurdly hot temps and absurdly long periods of time.  I don't have the very hot temps but I do have a lot of time.  The big ag websites say 30 to 45 days, but that's in the most ideal of ideal conditions.  I think I've heard something like 3 to 6 months in other conditions but I might be pulling that out of my ass.

Vote for yourself at www.ni4d.us!

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by: rossl @ Thu Oct 01, 2009 at 01:23:32 AM UTC

[ Parent ]

I don't know anything about (4.00 / 1)

commercial or municipal composting, but perhaps they don't do long times?

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by: count @ Thu Oct 01, 2009 at 01:51:31 AM UTC

[ Parent ]

Standards exist (4.00 / 2)

There are standards under development or already released from the big standards organizations.  ASTM D6400, "Standard Specification for Compostable Plastics" is one.  ISO 16929, "Plastics -- Determination of the degree of disintegration of plastic materials under defined composting conditions in a pilot-scale test," is another. Products that claim to be biodegradable should meet one of more of the standards. Unfortunately, payment is required to get the full text of the standards, but some engineering or chemistry libraries might have a subscription if you're curious.

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by: mental_masala @ Thu Oct 01, 2009 at 06:29:44 AM UTC

[ Parent ]