“Compostable Disposables”

Compostable disposables are a great idea for an eco-friendly party, right?  Well, maybe.

But let me back up a minute, first.  What is a compostable disposable?  Well, plastic (like, for plates, cups, silverware, etc.) can be made from petroleum.  That kind is definitely not compostable and you have to throw it out.  Plastic can also be made from corn, and dishes and so on made from that kind of plastic are marketed as being compostable.

Technically, yes, it is possible to compost corn plastic.  But the best authorities I can find (Smithsonian Magazine, for instance), say that it can only be composted in very hot, commercial composting facilities.  Being curious about this claim, my husband and I tried some experiments, with the help of a friend who has a very good home composting pile.  We took some cups and lids from my husband’s coffee roasting business to our friend.  The cups were paper lined with a very thin layer of corn plastic.  The lids were somewhat thicker plastic, but thinner than a plastic water bottle, and far thinner than a plastic plate.

The cups were shredded (with the assistance of the friend’s gentle pit bull) and put in the pile.  The lids went in whole (since the dog wasn’t interested in them).  In a reasonable amount of time (a few months, I believe), the paper and thin layer of corn plastic disappeared into the pile.  So far, so good.  That was last summer.  A few days ago, we were back at the friend’s house, and she handed us a lid that had been in the pile for about 9 months.  It was intact, whole, undisturbed.  Even her warm, active compost pile had not been able to digest even that much corn plastic.  Apparently, it does take a hotter compost pile to compost them.

Here is the lid after sitting in a nice, warm, active compost pile for almost a year.

But where do you find a commercial composter that will take corn plastics?  You can search for them at Find a Composter.  Search by state and then under “Paper and Compostable Products.”  You will find that they do not exist in every state.  For instance, while there are nine commercial composters in the state of Illinois, not one of them takes compostable plastic.  Connecticut, on the other hand, has one such facility; California has fifteen.  You might find, however, that many facilities do not take composting materials from households.

What is the solution, then?  If you are throwing a party and want to keep it as eco-friendly as possible, use ceramic dishes.  Rent them from a nearby rental house to reduce transportation waste.  If you have to use disposables, consider paper.  It is a renewable resource, like corn, and is much more compostable.  And, as we discovered, paper cups lined with corn plastic are actually compostable, even in a home compost pile.  If you need disposable utensils, though, there aren’t any really good answers.  Something is going to be thrown away, whether it is corn plastic or petroleum plastic.

So, be wary of the claims of compostability.  This is new territory and there are still a lot of questions to be answered.