You can leave your heart in San Francisco, but don’t you dare leave your plastic bag there. Or in a number of other west coast cities and towns, where the use of plastic grocery bags is banned. And state bans are coming soon, although the California state senate just rejected a bill for a statewide ban in the nation’s largest state.
Focusing on government policies masks the more fundamental question of what you and I should do about the receptacle we use when we head out for a loaf of bread and gallon of milk. What is the big deal about flimsy little plastic bags? Should we just return to the craft paper grocery bags many of us grew up with (even though they don’t have handles)?
Are these important questions or a campaign to make our personal lives inconvenient in order to supposedly save the planet? Well yes, they are important questions—especially since the volume is so high. As a nation, we do a lot of shopping for groceries and other products, so even a small impact of each individual choice is multiplied by billions each year. For the individual trying his or her best to reduce impact on the environment, the answer to the paper vs. plastic question isn’t simple, but it’s worth consideration.
In my ongoing search to separate green legends from the actions that can make good, solid contributions to health and sustainability, I’ve done some research on the decades-old question: “paper or plastic?”
To make all the bags we use each year, it takes 14 million trees for paper and 12 million barrels of oil for plastic. The production of paper bags creates 70 percent more air pollution than plastic, but plastic bags create four times the solid waste — enough to fill the Empire State Building two and a half times. And they can last up to a thousand years. Plastic, because it’s cheaper to produce, is the overwhelming choice of grocery stores across the nation — the average family of four uses almost 1,500 of these a year.
Why Not Plastic?
Although plastic is undoubtedly the most convenient choice, there are tremendous costs associated with the plastic choice, including toxic pollution, and costs of manufacturing, use (retailers do pass the costs along to consumers), disposal, and litter clean-up.
The plastic bag is an icon of convenience culture, by some estimates the single most ubiquitous consumer item on Earth, numbering in the trillions. They’re made from petroleum or natural gas with all the attendant environmental impacts of harvesting fossil fuels. One recent study found that the inks and colorants used on some bags contain lead, a toxin. Every year, Americans throw away some 100 billion plastic bags after they’ve been used to transport a prescription home from the drugstore or a quart of milk from the grocery store. It’s equivalent to dumping nearly 12 million barrels of oil.
Only 1 percent of plastic bags are recycled worldwide — about 2 percent in the U.S. — and the rest, when discarded, can persist for centuries. They can spend eternity in landfills, but that’s not always the case. “They’re so aerodynamic that even when they’re properly disposed of in a trash can they can still blow away and become litter,” says Mark Murray, executive director of Californians Against Waste. It’s as litter that plastic bags have the most baleful effect.
In our family, we do internal recycling of plastic grocery bags. When we still use plastic bags for convenience—especially with large grocery purchases—we reuse the bags as trash bags, which keeps us from using as many larger plastic trash bags.
Why Not Paper?
With all that nasty evidence, why don’t we just switch to paper and be done with it.
Of course, most paper comes from tree pulp, so the impact of paper bag production on forests is enormous. In 1999, 14 million trees were cut to produce the 10 billion paper grocery bags used by Americans that year alone. Paper bag production delivers a global warming double-whammy: forests (major absorbers of greenhouse gases) have to be cut down, and then the subsequent manufacturing of bags produces greenhouse gases.
The majority of kraft paper is made by heating wood chips under pressure at high temperatures in a chemical solution. As evidenced by the unmistakable stench commonly associated with paper mills, the use of these toxic chemicals contributes to both air pollution, such as acid rain, and water pollution. Millions of gallons of these chemicals pour into our waterways each year; the toxicity of the chemicals is long-term and settles into the sediments, working its way through the food chain. Further toxicity is generated as both plastic and paper bags degrade.
When you’re done using a paper bag, you have some options:
When you’re done using paper shopping bags, for shopping or other household reuses, a couple of things can happen. If minimally-inked (or printed with soy or other veggie-based inks) they can be composted; otherwise, they can be recycled in most mixed-paper recycling schemes, or they can be thrown away (which is not something we recommend).
If you compost them, the bags break down and go from paper to a rich soil nutrient over a period of a couple of months; if you throw them away, they’ll eventually break down of the period of many, many years (and without the handy benefits that compost can provide). If you choose to recycle paper bags, then things get a little tricky.
The paper must first be re-pulped, which usually requires a chemical process involving compounds like hydrogen peroxide, sodium silicate and sodium hydroxide, which bleach and separate the pulp fibers. The fibers are then cleaned and screened to be sure they’re free of anything that would contaminate the paper-making process, and are then washed to remove any leftover ink before being pressed and rolled into paper, as before.
Here Come Biodegradable Bags
Bioplastic bags, by contrast, are made from resources like corn that are significantly more renewable than trees. (It takes a lot less time to set up a cornfield than it does to regenerate a forest.) In one common process, corn starch is fermented into lactic acid, which is then mixed with a variety of additives to give it polyethylene-like properties. The source material needn’t be corn—potatoes are also popular, and Japan’s Hitachi Zosen is experimenting with cassava. There are also processes that use microbes to ferment cane sugar and vegetable oils.
Bioplastics still have their problems. For example, they usually lack the strength of polyethylene, meaning that they’re more readily used as simple food wrappers rather than as grocery bags. The bottom line on bioplastic bags is that they’re not going to show up in mainstream supermarkets until prices come down significantly.
So, while it’s good to have the alternative (and to recognize the innovation it represents), bioplastics aren’t quite ready to save us from the paper or plastic debate.
Many agree that there is no good answer to the “paper or plastic” question, opting instead for the third way:
Ultimately, neither paper nor plastic bags are the best choice; we think choosing reusable canvas bags instead is the way to go. From an energy standpoint, according to this Australian study, canvas bags are 14 times better than plastic bags and 39 times better than paper bags, assuming that canvas bags get a good workout and are used 500 times during their life cycle.
Here’s where we’re headed as a family and what I’ve taken away from my exploration of this issues:
1. Use canvas bags for all grocery runs except the big (for us twice-monthly) grocery runs. We have a quite a few canvas shopping bags; there are even a few in the car. That’s not the issue. We just need to build the habit of remembering to carry a few into the store each time. We’ve got to stop the use a plastic bag to carry home a prescription or a jar of peanut butter.
2. Use plastic when necessary. For large grocery runs, we’ll use the plastic bags, but recycle them as our household trash bags. They’re smaller than the tall kitchen bags, requiring us to change them frequently, but it saves money and it also cuts down on our plastic use.
3. Use paper when we can compost. We’d like to begin composting, and when we begin that practice, we’ll try switching to paper and composting the paper bags. I am inclined toward paper over plastic simply because they can hold so much more and clerks pack them so much better. (Perhaps I’m just remembering my last-century days as a high-school grocery boy).
What’s your plan?