Tuesday, November 04, 2008

Wrapped in Plastic

First Printed in the Montague Reporter Nov 2008

I pull a gallon sized Ziploc bag from its sunny yellow box, one of several boxes my mother, who shops at Costco, sent home with me last weekend, and swallow the guilt as I add yet another virginal plastic bag to the relatively permanent archive of plastic things in the world.

Just to be clear, I don’t buy plastic bags. Well, not unless it’s for a good cause like packing away the twenty pounds of wild low-spray blueberries we raked last summer. I tell myself I’ll reuse them, and I do, from storing bagels, to blueberry muffins, to banana bread before tossing them in for a spin in the wash whenever a greasy film builds up. But then the inevitable happens. The plastic zipper tab breaks off, or the blue and yellow tracks warped by warm water and dryer heat no longer join. For a while the bag limps through still storing food, closed up with a rubber band, or rolled up tight and tucked away. But that only puts off its fate for so long – eventually the plastic shows its age, as small cracks and holes begin to let in air or let out drips of last night’s soup.

That’s when it’s pitched into the trash. I’d add them to the Stop&Shop recycling (or down cycling) pile – which allows shopping bags, dry cleaning bags and newspaper bags - but wary of “contaminating” plastic batches with Ziplocs I refrain, and make a note to ask Stop&Shop about this.

As frugal as I am about Ziplocs and Saran wrap, my mother is not. But it wasn’t always that way. I can still recall my envy over the little plastic sandwich baggies Amy Ellis, my best friend in grade school, pulled from her lunch box each day. Her mother, a decade younger than my 42 year old mom, was far more “with-it,” or so I thought. If there was a new product, Amy had it. While her sandwiches were moist and soft, good material for a lunch-time trade, mine, in its wax-paper sandwich bag, couldn’t compare. Now the shoes are on my slightly older feet and I refuse to pack my kids’ lunch in plastic baggies. Just check out the garbage pail in any school room around the country and you’ll find plenty. Their total useful life-time? About three hours.

According to the history of plastic bags, those little baggies, thin sheets of blown polyethylene film sealed along three sides first came into being around 1957, roughly twenty-four years after the discovery of the stuff, and ten years before the ubiquitous and larger, produce bag.

Plastic produce bags, primarily LDPE or low density polyethylene, now fill the cotton shopping bags of the most plastic-wary consumer whether they’re shopping the farmer’s market, the local co-op, Whole Foods or Big Y. So I was heartened last week when I loaded my bagels into a recycled plastic produce bag at Whole Foods. If only the darn thing didn’t break open and spill six bagels onto the floor! I’m sure in time they’ll get it right.

Like sandwich baggies, by some estimates the useful lifetime of produce bags is measured in minutes, or however long it takes to stuff some string beans into the bag, hit the check-out counter and dump them into the colander for dinner. Though the most fastidious of us might reuse them or cart them back to Stop&Shop for recycling, plenty still end up in the trash.

Like all plastics, plastic baggies flow from the crude oil tap which is refined and distilled before cradling our organic broccoli. Crude oil is a complex mixture of hydrocarbons – carbon and hydrogen containing molecules. Some are long, some are short. They are straight, or branched – but all have a carbon “back-bone,” or a chain of carbons C-C-C-C. For years I had a small vial of crude oil in my office, rescued from the Valdez Oil spill, the label thanked me for helping to remove some ridiculously small percentage of the original spill (it now sits somewhere on my son’s science teacher’s desk – beseeching impressionable minds to think more deeply about the consequences of using oil.) This particular crude is the darkest of browns, a thick balled up tar-like substance floating atop the Prince William Sound water captured along with it. It is hard to imagine the link between the transparent filmy Ziplocs in my pantry and a vat of crude oil.

During distillation successively lighter fractions are boiled off and collected, the shorter carbon chain the lighter the fraction. Gasoline for example is “light,” and one of the first fractions collected, while the heating oil that warms our house is thicker, heavier and consists of longer carbon chains. Carbon chains can also be “cracked” into shorter chains, like ethylene, a simple two-carbon molecule. Ethylene is a highly versatile molecule used in hospitals and medical offices for sterilization, fruit ripening (it is also a naturally produced fruit hormone which initiates fruit ripening – try storing some apples next to an overripe banana and see what happens), antifreeze, a one-time gasoline additive, and plastics.

It is one of the highest volume organic (carbon containing) chemicals in production. According to a recent report by
SRI consulting in 2006 “…global ethylene production amounted to about 110 million metric tons, with an estimated value of $122 billion.” 110 million metric tons, and guess what? Over half of that goes right into the production of polyethylene plastics including bags and plastic wrap.

“Everyone’s asking about plastic wrap in the microwave,” says my mother one afternoon. Apparently some of her friends had read or heard about the email promising death and destruction by dioxins and other “toxins dripping into your food.” For years she’s been using plastic wrap when reheating. Her reheated food is moist and her oven clean. I don’t cover, and my oven is encrusted with splatter and my food dry. Turns out the email was a hoax, but – according to both the American Chemistry’s Plastic’s Info site (Better Living with Plastics), and the FDA (for what it’s worth these days), consumers should be wary of combining their wrap with their food when microwaving. According to the Plastic’s Info, site, “..most manufacturers recommend leaving at least an inch between the food and the wrap covering the dish. This is to prevent the plastic wrap from melting, which could result from contact with extremely hot foods.” Not to mention allowing chemical additives present in some of the clear cling wraps to leach other chemicals into your food.

Plastic wraps are made from LDPE or polyvinyl chloride (PVC). Concern about toxics leaching from PVC wrap started the rumors flying. Although plastics are incredibly versatile materials, sometimes they are tweaked with chemical additives to get just the right clinginess, or color or flexibility. That meant diethylhexyl adipate (DEHA) in the case of chlorine containing cling wraps. Problem was under the right circumstances, like heating in a microwave, particularly heating things with high fat content, like cheese or meat, DEHA, a reproductive and developmental toxicant (although so far as we know just at relatively high doses) migrated from the plastic wrap resting on top of last night’s Buffalo Chicken Wings into the wings.
While the FDA acknowledges that substances like DEHA can and do transfer from plastic to foods during reheating, the controversy is over how much leaches and how toxic. While FDA maintains whatever leaches out is safe, some countries have banned the additive, while S.C. Johnson, producer of the granddaddy of all cling-wrap, Saran, switched from PVC to LDPE, winning an EPA “Designing Greener Chemistry Award” in the process.

Now, if we just can figure out how to consistently recycle all that wrap and all those LDPE baggies – we’ll all be a little bit greener.