I’m in charge of doing the dishes. We let them stack up all day and then I do them all in one fell swoop before I settle in for the evening. It’s ok. Doing dishes is one of my favorite chores, so it’s not really work to me.
This also gives me the opportunity to read labels and decide which plastic containers are recyclable and which ones are tossable. It was not too long ago that these cute ovacious baby spinach containers started showing up in the house. I’m a sucker for containers and shapes so I wanted to keep a few of these to pack salads to go.
Anyway, one day I turned one over and noticed that it was not marked with a recycle PETE number, but instead said NatureWorks PLA Compostable! Compostable plastic?
I had put a few of them into the compost bin since then, only to find them later in the garbage bin. But it was only today, when I finally had to prove to the housemate that there was no reason to toss these containers and that they shouldn’t be removed from the compost bin when I wasn’t looking, that I looked up NatureWorks and PLA on the web.
PLA is the acronym for Polylactic Acid or Polylactide, a versatile polymer made from lactic acid. The bio-plastic life cycle process goes something like this:
- Field corn is harvested and broken down into its food and feed components.
- One of these components is corn sugar, or dextrose.
- The dextrose is fermented and distilled into lactic acid.
- The lactic acid is made into NatureWorks PLA.
- The PLA is formed into plastic containers and bottles.
- Once used, the PLA can be broken down in the compost.
- PLA can also be incinerated or chemically recycled back into its base monomer unit of lactic acid.
- In theory the compost can then be used to grow more feed corn.
Really cool, I think!
NatureWorks PLA has been around for a few years now, and I think I am only discovering it because most of the produce I buy is loose in the bins at the stores and markets. I rarely buy packaged produce.
Beside these cute ovacious containers, NatureWorks makes any number of food containers, from water bottles, to clamshells (for your food to-go), drinking cups, bowls and lids, cutlery, and any number of food containing items. So turn those plastics over and look for the PLA Compostable lettering on the bottom – then do the right thing!
The only thing about bio-plastics is that they need to be recycled through a commercial composting system – like your city composting facility – rather than a backyard composting bin for it to break down properly.
7 Comments
There are a lot of problems with PLA – If we made all of the plastic disposable items used in the world every year out of PLA, it would take one hundred million tons of corn to make it. That would lead to mass starvation in the third world, as that represents at least 10% of the world’s grain supply. It also takes a huge amount of diesel to grow, fertilize, ship, and process this corn, and as a practical matter, it is also not recyclable-In fact, the recyclers are trying to get PLA banned because it gets mistaken for PET, and ruins their PET batches. The alternative? Recyclable Oxo-biodegradable plastics and biodegradable-plastics made out of an otherwise useless industrial byproduct, naphtha. See http://biogreenproducts.biz for full information. -Tim Dunn
I would hope that eventually we would move away from using plastics altogether in food containers, so I’m not promoting PLA in any way to be the be-all-end-all solution to the plastics recycling problem.
Berkeley has already, years ago, banned styrofoam, and life adjusted fairly fast, so I’m not worried too much about people’s adaptive reflexes once they are mandated or educated into using different materials.
But I think a *combination* of solutions will aid in not hogging up just one resource (like corn being used for PLA and bio-fuel) for bio-degradable items like plastics.
Anyway, I hope that what people take away from the story is that they should pay attention to what the container says on the bottom so that it gets recycled in the right place.
You need to do a little more reading about PLA. Tim’s comments are on the mark. The other thing not mentioned is if you put PLA into a “backyard” compost heap, you will be waiting a long, long time for it to turn into compost. The company specifically notes that PLA requires commercial composting for it to decompose. There exists almost no commercial compost facilities accepting anything other than yard waste in the U.S. And with no recycling for PLA in operation, your PLA packaging will be destined for either a landfill or a WTE facility just like the materials it replaced. Sorry to break the bad news to you.
If you read the last paragraph in the post, you’d see that I mentioned that the PLA product has to go to a commercial composter.
The product that inspired this post is ‘I Love Organic Girl’ Baby Spinach. They have a list of composting facilities for their PLA containers.
http://www.iloveorganicgirl.com/og/sustainability/find_a_composter/
And the point is, again: “I hope that what people take away from the story is that they should pay attention to what the container says on the bottom so that it gets recycled in the right place.”
I would like to address the issue that Kimba points out, that you need to pay attention to the decisions that you make as a consumer, and how it affects us all. I am with organicgirl, an organic produce company, and we do use PLA #7 plastic containers for all our organicgirl products we produce in clamshells. I’d like to clear up a misconception that Mr. Dunn states, and that is the use of corn to make the trays. It’s plant startch, not necessarily corn on the cobb, that is used to make PLA. PLA was initially made from corn, but many improvements have been made since it’s infancy many many years ago. To clear this up, PLA is gleaned from the plant stalk and leaves left in teh field after the vegetable has been harvested. The crop would usually be disked under in preparation for the next field, but PLA technology allows the field remenants to be harvested again to produce the lactic acid to make the PLA resin. There is no stealing vegetables from 3rd world countries to make PLA, or anything outrageous like that.
Also, to address Mr. Bryant, it is recommended to send your PLA containers to municipal composting facilities because of the wide variability in home composting. Home composting requires a specific carbon nitrogen ratio, surface area, aeration, moisture, and most importantly temperatures of between 90˚F – 140˚F (32-60˚C). We have had consumers home compost successfully, again, it’s just not recommended due to the variability of composting piles and individual knowledge of composting.
In addition, with organicgirl choosing packaging from plants (PLA) and not oil (PET), we have also greatly reduced our packaging environmental footprint. Based on our environmental calculations for 2008, we have cumulatively saved approximately the fossil fuel energy equivalent to over 135,000 gallons of gasoline and reduced green house gas emissions equivalent to driving a car over 3,000,000 miles (based on switching our annual consumption of containers from PET to PLA). organicgirl has chosen to impact what we CAN influence for a positive change, and today that is the origins of the plastic. Hopefully you agree this is a great step in the right direction.
Thanks organicgirl!
I think part of the confusion lies in what part of the plants go into the product. Even the NatureWorks web site talks about field corn being used, so it would be easy to think that *only* the actual corn kernals were part of the production.
Thanks for clarifying that!
Here is a really interesting article from the Smithsonian on PLA:
http://tinyurl.com/bsu5us