SunChips®, in keeping with its healthy snack identity, have added "planetary health" to its mission. The Frito-Lay company chose the SunChips® line as launch pad for "the world's first compostable chip bag." Then they set the bar higher by substituting a plant based polymer for the typical petroleum-derived plastics of most snack bags. As an avid composter and recycler, I wanted to dig deeper into compostable packaging.

Just what does compostable mean?

We gardeners debate the compostability of some materials like pine needles or cat litter. We usually end up in an inconclusive exchange of anecdotal evidence. That 's not good enough for industry (or government.) There is an organization of highly educated, technical people devoted to just about everything testable, including assuring that when a product calls itself compostable or biodegradable, it really is. ASTM International (originally the American Society for Testing and Materials) has several "standards" (set of rules) concerning compostability. In a (biodegradable) nutshell though, commercial compostable packaging is designed and tested for performance in a commercial, managed, hot compost. Conditions in your casual backyard compost can be radically different.

Most backyard compost is cold

I am just guessing but I feel confident in asserting that most backyard compost is not carefully managed hot compost. So will compostable packaging perform, or poop out, in the home system? The chip bag's creators tested their bag not only in an industrial style hot compost, but in a less managed, more homestyle compost. The bag performed similarly in both situations, possibly suggesting that the heat of the compost is not a critical factor in the breakdown process.

My experience- yes it works

In May, I bought the bag of SunChips® in the compostable bag and munched away. (Collateral comment- they are a tasty snack, with a texture sort of halfway between tortilla and potato chip.) I then used the empty bag to collect a few days worth of coffee grounds, egg shells and vegetable peelings. The bag resisted moisture during that time just as a conventional chip bag would. (However, when my son saved fruit peels and scraps in a SunChips® bag, it did eventually leak.) Then I dropped the open bag into my compost bin, letting it socialize with more rural neighbors like pulled weeds. A week or two later (or a month? this is a very unmanaged compost) the bag seemed completely unchanged. I thought I better step up the rot potential of this thing. I rearranged the compost and got the chip bag well mingled with more decayed, moist parts of the compost. Then I completely forgot the whole thing for a few months.

Somewhere around September I resurrected the chip bag. At that point, with around a dozen weeks of summer heat and humidity, the bag was actually breaking down. I mean that in a more literal sense than usual. It seemed to be breaking into friable strippy pieces rather than all becoming slimy or mushy the way most things rot in the bin. In the photo above, the bag on the left spent months in the compost. The bottom half broke down more completely than the top, maybe because the bag was initially half filled with kitchen scraps. It may take some retraining of my brain to accept the plasticky shiny fragments as OK in the soil until they become unrecognizable.

But questions remain

Is this bag good for my compost? Tests on the SunChips® bag certify it as clean with regard to heavy metals or ecotoxicity. Of course that's good news. Just don't expect the chip bag to perform magic in your compost bin. Plastics are really good for food packaging because of their waterproof nature and chemical stability. Those characteristics are just the opposite of what makes for good hot active compost. The polymer, like other plastics, is an organic chemical composed entirely of carbon, hydrogen and oxygen. Treat the chip bag as a 'brown' with the long life of an oak leaf in the compost. Shredding or cutting the chip bag into smaller pieces will hasten its breakdown, just as that helps other tough-to-rot items in your bin.

When can we see more biodegradable products? While claims of a company's environmental awareness make for good press, their bottom line is, well, their bottom line. Fortunately, the biopolymer industry is growing, and material costs are declining. Biodegradable and compostable items are sneaking onto supermarket store shelves and into restaurants. The world's second compostable chip bag is on the works, and a kraft paper bag for frozen foods is now used by Stahlbush Island Farms. Click this link to explore a few more earth friendly disposable products. Biopolymers resist wetness well enough to work for short term food storage. If the cost of biopolymers falls below that of that of traditional plastics, stand back. Manufacturers will jump at cheaper production costs, while marketing teams will quickly embrace the compostable packaging angle as a new consumer enticement.

How will biodegradable products fit into the waste stream? Step one is the production and sale of biodegradable products, step two is actually composting them. Many areas still collect mixed waste and do not provide separate collection of recyclables. "Compostable" items that end up in a modern sanitary landfill are not fulfilling their destiny. Where collection of recyclable glass, metal, plastic and compostable yard waste is provided, citizens fail to fully support the program. Will compostable packaging be clearly labeled so that those of us who wish to compost can identify them readily? Each level of complexity to waste collection and processing adds cost, and frustration for government and consumer alike. Would the biodegradable items be accepted with yard waste? If they end up with plastic recycling, will they contaminate that product?

When will we consumers decide what we REALLY want? There's been a new plot twist in the chip bag story. Consumers are complaining that the bag is too crackly. Yes, really. It seems the future of the earth is minor concern, when compared to waking your roommate or disturbing the adjoining cubicle with your excessively crackly snack bag. Consumer protest has been loud enough to force Frito-Lay back to the drawing room in search of a quieter compostable snack bag; it's unclear how much inconvenience the general population can tolerate for the conservation cause.

I can't promise that compostable packaging will determine my chip choice. (Or my snack choice, for that matter. My compost would be better enhanced by apple peels than a biopolymer bag.) I can't swear that I'll keep up with every biodegradable package that comes my way. Committed as I am to composting, trying to select biodegradable packaging and remembering to put it in my compost bin may be one complication too many for my busy days. I'm happy to report that the SunChips® bag seemed to perform as advertised, and that the eco-sensitive options for consumers and retailers are much greater than I imagined.

~~~ ~~~ ~~~ ~~~ ~~~

Frito-Lay's SunChips® pages where you can read their original information on the bag, composting, and the chips, too.

Treecycle sells a wide assortment of biopolymer and starch based disposable products. Click here

Fact sheets from Cornell University on Municipal Soild Waste Composting may be of interest. Click here to link to Fact Sheet #1