Compostable/Biodegradable Bags: Getting to the Bottom of It

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After we posted Recology manager Chris Porter's clarification on so-called compostable/biodegradable bags, we got the following email from reader Lori Fisher, a Pacifica resident:

Checking with Recology, I got a different answer from someone else regarding biodegradable bags. The BioBags would get caught on their sorting/moving tables. I had called asking if I could get a compost pail I had seen a neighbor using to work with my new BioBags I purchased at Costco. BTW: No compost pail is available.

Now some of what is on the box of BioBags -- Food Waste Collection Bags Certified Compostable:

"BioBags are approved by the San Francisco Department of the Environment for their food waste collection programs."

"BioBags are approved by King County Solid Waste Department for their food waste collection programs."

"This certification assures that BioBag products meet the specifications found in ASTM D6400 and will compost rapidly & safely when placed in a municipal or commercial composting facility."

"BioBag products are made from starches derived from plants, vegetable oils, and the world's first patented compostable polymer. No polyethylene is used in the production process. We are fully certified by the Biodegradable Products Institute (BPI) and meet the requirements of California law regarding environmental claims of plastic bag manufacturers." (This is a USA product)

Website for more info: www.biobagusa.com

Facts & FAQs: http://www.biobagusa.com/biodegradable-bags.html

About Mater-Bi: http://www.biobagusa.com/mater_bi.htm

A brown bag cannot hold your greenwaste from the kitchen to your outside container without falling apart, especially when you have "wet" greens. Think of the Glad garbage bag commercial. I don't want that kind of mess to clean up. (Editor's Note: I double the bags, ordinary brown-paper sandwich sacks from Costco.)

Tell me why we cannot use these BioBags? San Francisco outlawed plastic bags but allows these special bags in its compostable waste collection.

Lori Fisher

Comments

[Larry Rosenstein]

Here's a short article on making a compost bin liner from a couple sheets of newspaper:

http://www.sfgate.com/homeandgarden/article/How-to-make-a-newspaper-recycling-bucket-liner-3498094.php

[Matt Wynkoop]

As Chris mentions above, it's important to understand where your waste management company sends its organics waste (compostable waste). Every commercial composting facility is different, operates a different commercial composting process (curing time; compost temps), and therefore accepts different types of compostable waste. Some just accept yard scraps -- some accept yard+food waste -- some accept yard+food+compostable bioplastics.)

For instance, a facility that turns out compost as a finished product in 45-60 days would not likely be able to accept compostable bio-plastics (e.g., Sonoma Compost) because compostable plastic needs a longer period of time to break down, but a facility that operates a longer process, and ideally keeps the heat high for an extended period of time (e.g., Newby Island {Milpitas} or ZBest {Gilroy}) do accept compostable plastics. So the question here is: Where is Recology sending your waste? It operates three to five different commercial composting facilities in Northern California.

One thing to note is that San Francisco banned "single-use plastic take-out bags," something you might get at the grocery store or corner mart -- mainly because they contribute to so much litter and cannot be recycled. Compostable plastic can-liners are a different thing, and the S.F. accepts those -- and Recology is S.F.'s waste service provider -- so, unless I'm mistaken, they accommodate those compostable plastic trash liners. (But Recology might send Pacifica's waste to a different facility than it sends S.F.'s to.)

S.F. and Recology accept compostable bags and liners that are bpi-certified. You can see the list here: http://www.bpiworld.org/

Another thing to consider is whether the compost facility turns out OMRI-approved (organic farming-approved) compost -- as compostable bioplastics are not approved for OMRI-certified compost.

IT'S AN EVOLVING INDUSTRY!

And one more thing -- compostable and biodegradable have different definitions! Learn more: http://worldcentric.org/images/newsletter/Compostable%20vs%20%20Biodegradable.pdf

[Michele Pixa]

The best way to handle food scraps in the kitchen is to use a small compost pail that you keep on the kitchen counter or on the floor. They can be purchased online, at Rainbow Grocery in San Francisco, and possibly Whole Foods. To use any kind of bag defeats the purpose of being ecological. Once you dump out your pail into the green waste bin, you can rinse out the pail with an outdoor spigot, or rinse it out at the kitchen faucet.

[Chris Porter]

The following is the answer my Recycling Coordinator, Felicia, sent to Ms. Fisher:

Good Afternoon Ms. Fisher,

Thank you for sending this over to me. I appreciate the time you have taken to research compostable/biodegradable bags.

As you mentioned, there are few bags out there that have been tested and approved by some agencies as compostable and are accepted in their curbside collection programs for organics. Unfortunately, the truth is that these bags do not completely biodegrade within the time the organic material sits at the processing facility. Most of these bags biodegrade in as little as 60 days but can even take 180 days or more at a commercial processing facility. (You will see that this information is not easily found). The organics processor we use has a processing/compost time of 45-60 days. This means these “compostable” bags are found at the end of the processing time and have caused us some problems. This is the reason why we currently can not accept compostable/biodegradable bags in our Organics program.

Rest assured, this issue is widely known in our industry and groups like the CAW (Californians Against Waste) are actively working on resolving this and other issues and making sure that what is being advertised by these manufacturers are correct.

I hope this clears up some of your questions. Again, thank you for your time and if you have any further questions please feel free to contact me.

[Chris Porter]

pol·y·mer   /ˈpɒləmər/ Show Spelled[pol-uh-mer] Show IPA
noun Chemistry .
1. a compound of high molecular weight derived either by the addition of many smaller molecules, as polyethylene, or by the condensation of many smaller molecules with the elimination of water, alcohol, or the like, as nylon.

Most polymers have some type of polyethylene in them. I will do research on why San Francisco accepts this one brand, BioBag, and keep the readers up-to-date.