The Compostable Cup Trials

The Compostable Cup Trials

Some years back, I ran across some compostable water bottles at a Starbucks in Seattle and, because of the skepticism deeply embedded in  ProfessorRoush’s academic soul, I thought it would be a neat idea to try to bring them back in my luggage and test their compost-worthiness at home.  Unfortunately, the TSA must have deemed the empty bottles in my checked bags as a potential terrorist threat because the bottles were not in my suitcase upon my arrival at home.

I was more fortunate last year when I ran into these certified compostable cups at a pizza parlor in Fort Collins, and I was able to ultimately get them into my 65 gallon Lifetime tumbling compost bin by sneaking them home in my car past the marijuana-alert sentries on the Kansas border.

These Eco-Product cold cups are, as printed on the cups, certified by the BPI, or Biodegradable Products Institute, to be compostable in a municipal or commercial composting facility.  The BPI is a “multi-stakeholder association of key individuals and groups from government, industry and academia” that tests products by written ATSM standards and certifies them. Materials tested by the BPI must include the ability to “biodegrade at a rate comparable to yard trimmings, food scraps and other compostable materials, such as kraft paper bags,” and they must “disintegrate, so that no large plastic fragments remain to be screened out.”

I placed the new cups pictured in the top photo into my tumbling compost bin on 5/26/2014, along with mature compost and grass clippings.  You can see immediately above this paragraph several periodic photos taken over last summer, a time span when numerous additions of kitchen scraps, grass clippings, other organic materials, and water were composted in the pile alongside these cups.  The cups did not disintegrate, as you can see, although they flattened and tore, probably from the repeated tumbling alongside wet and heavy clumps of compost.  The organic materials in the bin repeatedly became decent, black homogeneous compost with which any gardener would be happy.

This week, almost 11 months after the start of the experiment, I again opened the compost bin and found the cups as shown.  Now, in fairness, I should note that the BPI website states clearly that these products are not meant for home compost piles, but only for “well-managed municipal and commercial facilities.”  Home composters “typically do not generate the temperatures needed to assure rapid biodegradation of this new class of materials. For this reason, claims are limited to larger facilities.”

That’s all well and good, friends—I can accept that ProfessorRoush is likely a terrible composter—but shouldn’t we at least expect that now, 11 months later, the ink would faded and illegible?

Furthermore,  while I’m on a rant, what exactly constitutes an “acceptable municipal facility?”  Does my local county recycling facility, which routinely composts leaves and other materials, qualify?  It isn’t listed at the website printed on the cups, nor is any other facility within 50 miles of me.  How many of these cups would actually make it into a “well-managed commercial facility” anyway, rather than just being tossed into the restaurant waste cans with all the other debris and taken to the usual county shredding facilities?  How much more energy and chemical processing is involved in making these cups over the standard red plastic cups that we love to make so much fun of?  Which is more likely to be recycled and have the least long-term environmental impact?  Is this merely more marketing misinformation to muddle the minds of the masses?

I can’t help thinking that while compostable cups make us all feel good, this whole certification system seems designed just to keep us from noticing the man behind the curtain while we slurp the Koolaid of environmental ecstasy.  It is only a matter of time before we’ll hear offers for a free carton of these cups with every thousand carbon credits we purchase.

Posted by

James Roush
on May 11, 2015 at 7:26 am, in the category Guest Rants, Ministry of Controversy.


    • Lydia
    • 5th November 2015

    That example does not make sense. “Organic” is certified. “Compostable” is not.

    • Jan
    • 15th August 2016

    On the other hand, do you really want those chemicals and polymers, etc. as one of the ingredients in your earthy, organic compost? It is similar to those polymer crystals people put in their potting mix to hold water. That stuff eventually breaks down and now those artificial ingredients are part of the potting mix.

    • Margo
    • 29th October 2016

    My first thought was the same as Jan’s – what are the cups made from and do I want it in my compost? I volunteer at local farmers market at their zero waste kiosk helping sort the trash into landfill, recycle, and compost bins. Generally these cups go in the recycle bin but I’ll ask the composting group if they have tried to compost them. I’m curious now.

    • Maureen
    • 23rd November 2016

    I put a “compostable” sun chips bag in my compost bin over 3 years ago. It’s still there.

    • skr
    • 17th December 2016

    I have a compostable fork and spoon in my pile going on 4 years now. By the way they looked last year, I imagine they are still in there.

    • granny gardener
    • 17th December 2016

    that’s funny. I too put a sun chips bag in my composter and left it there for three years with absolutely no change to the bag at all! Noisy and not degradable! lack of success all around!

    • Matt
    • 17th December 2016

    I have cut up a “compostible” cup and then some utensils that I have come across. Both have “disappeared” in the compost over the year… but I will say that the parts that were exposed to the sun became brittle very quickly….. vs the parts that I purposefully moved to the center of the 4×4 compost pile.

    • Garden Rant
    • 17th December 2016

    Great rant! Susan

    • admin
    • 18th December 2016

    Oh, but Benjamin, it’s Cornhusker tradition. Living there in the heart of it all, you are less safe than if you drew a picture of the Prophet Mohammed and carried it down the streets of Mecca!

    • Matt
    • 18th December 2016

    wow… those are some posts you have there on that huskers posting. I wonder what those same people would say if you walked over to there house with a bunch of huskers posters, huskers napkins, huskers cotton t-shirts and just dumped them on their lawn…. with a sign saying … it’s okay … they are biodegradable!

    • Laurie Lewis
    • 18th December 2016

    We have several “compostable” seedling pots in our compost 4 years later!!

    • admin
    • 18th December 2016

    Yikes, I’m going to have to keep my trial going a bit longer then, aren’t I?

    • Bridget
    • 18th December 2016

    Compostable Easter grass. I hate plastic Easter grass. It gets everywhere when you store the kids’ baskets for the rest of the year. When I saw some labeled as “compostable” I was happy to give it a try, thinking I could put it in the tumbler and be done with it. Six years later, and I’m still picking little ribbons of bright green plastic out of my garden.

    • Denise
    • 18th December 2016

    I just found your blog and love it!
    Regarding the compostable plastic I agree with some other comments about not wanting the chemicals in my compost. I think the thing is that we are so overwhelmed with messages, entertainment, and constant slogans that we “buy” buzz words even though they mean little to nothing – ala “natural.” My concern is that while these plastics would eventually break down to where I couldn’t see pieces – what sort of chemical will my plants, and then I & my family, be eating. I think it’s a load of crap.

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