The Shopping Bag Debate
Source – Greenfeet Blog
The following article is an updated version of one I wrote several years ago. It has had over 30,000 readers in the last 3 months and has prompted hundreds of comments and lively feedback. I do hope you’ll find it interesting and feel compelled to share your thoughts and insights.
Keep in mind, this is an objective, broad look at the debate of paper vs. plastic grocery bags. Is it a complete, scientific assessment? No. However, it’s a good start, filled with facts and one that I hope gets you thinking the next time you’re confronted with the choice. Enjoy.
Paper or Plastic? Stupid Question
You step up to the register, the cashier asks if you’ve found everything ok and then hits you with the inevitable question: Paper or plastic? I hope the answer would be “No thanks – I brought my own”.
Let’s just pretend it’s one of those rare days when you’re caught without your reusable bags (it’s ok – I’ve been guilty of this a time or two) and you have to choose – will it be paper or plastic? How do you decide?
I realize this is a hotly debated topic and my goal is to simply point out the pros and cons of each option. Let’s face it – paper and plastic are both taxing to the environment. Once you’ve read the information below, I hope you’ll feel more confident in your decision.
The Plastic Bag – a bit of history
These days, most plastic bags are made from a type of plastic called polyethylene. 80% of polyethylene is produced from natural gas – an abundant, yet non-renewable resource. Polyethylene, as a raw material, can be manipulated into any shape, size, form or color. It’s watertight and can made UV resistant. It can be printed on and reused many, many times. In many cases, it can be recycled but is not considered “cradle to cradle” meaning it cannot be recycled over and over nor returned to an organic state.
According to a timeline published by plasticsindustry.org, the first plastic bags were baggies and sandwich bags on a roll introduced in 1957. The industry continued to grow and between 1974-1975 retail giants such as Sears, J.C. Penney, Federated and Allied adopted plastic bags for store merchandise. When did the plastic grocery bag hit the market? That would be 1977, the year Jimmy Carter was sworn in as our 39th President, Star Wars hit the theatre and Apple Computer was incorporated.
In 1996 it was estimated that 4 out of 5 grocery bags used were plastic.
Where does plastic go when thrown away?
< 2005 EPA research shows that approximately 5.2% of plastic bags are recycled. I was a tad disappointed to hear that number too. On the bright side, the number of pounds of plastic bags recovered according to plasticbagrecycling.org is a 24% increase in 2006 over that of 2005. This is based on a report produced by the American Chemistry Council. So, while the overall number is abysmally small, it is on the rise.
Plastic bags can be melted and reformed into products such as plastic lumber used on decks, fence material, park benches and other industrial and residential goods.
Where do the other 94.8% that aren’t recycled go? They typically end up in your local landfill. How long until they break down? No one really knows but we can speculate. The SPI (the plastic industries trade organization) openly admits on its website that most plastics don’t biodegrade – that’s the process of breaking down completely into organic material which is then assimilated back into the soil. Most plastic will photo-degrade. This means, over time and when exposed to ultraviolet rays from sunlight, the plastic material’s chemical “chain” starts to break down resulting in microscopic particles that mix in with the soil (more on this later). How long that process takes is not clear.
Plastic, in any form, has only been around a little more than half a century. Even the most conservative scientists believe it will take at least several hundred years for plastic to photo-degrade when exposed to the correct conditions. I’ve heard the range debated somewhere between 500-1000 years. Whatever the number, plastic experts agree that it’s a long, long time and we have not had any first hand evidence of its decomposition. Most likely, every single piece of plastic created is still here on this planet. That’s a lot of plastic.
Let’s take a quick look at the energy consumed and pollution potential of the plastic bag. According to Boustead Consulting & Assoc. Ltd who produced a recent report for the Progressive Bag Alliance, polyethylene uses less energy, oil and water (potable) than paper bags made with 30% recycled fibers. Their study also shows that plastic grocery bags emit fewer greenhouse gases and less solid waste.
This report also admits that reusable bags may be the preferred alternative (see, told ya!) but points out that most people don’t remember to bring them. Ahhh…that may be true, but I believe that people are smarter than that and when they understand the value associated with bringing their own bags, they’ll remember. But I digress….
Plastic not being recycled can be burned yielding roughly 10,000 to 20,000 btu per pound, most of which can be used to create electricity. This can help to reduce the overall sulfur emissions from coal.
The burning of plastics has its cons. Inks and additives found in plastic can create dioxins when burned as well as emit heavy metals into the air. I must note that the plastics industry claims that more and more manufacturers now use water based inks. However, the ash itself is toxic and needs to be disposed of in toxic waste dumps. Despite these ink improvements, do you believe the continued burning of plastics for energy use justifies the continued consumption of limited natural resources?
Plastic also impacts the environment through landfills. Plastic does not readily degrade in a landfill, hence, your yogurt container will be there for centuries. Biodegradable plastic is really non-existent. Biodegradable plastic is typically made from wood fibers mixed with plastic. When the bag is disposed of, the wood fibers break down leaving millions of tiny plastic pieces to mix in with the soil. There are newer, compostable plastics derived from plant material on the market but those are not the focus of this piece.
I take issue with these microscopic particles that mix in with the soil. One could reasonably argue that we wouldn’t know these particles existed in the soil and that they wouldn’t affect the growth of plants. Fair enough. Personally, I hold the belief that healthy soil equals healthy food. Adding plastic to the mix seems to go against nature. However, my greatest concern is the potential effect on animals and aquatic life who can’t discern between digestible particles and these microscopic plastic bits that their systems do not accept as food (this is assuming most animals don’t wash their veggies like we do). These particles will either poison animals and aquatic life or become part of their system. These animals are then ingested by larger prey, so on and so forth, until it may very well end up on your dinner plate or at the local sushi bar. I’ll pass, thank you very much.
An argument can be made that plastic decreases landfill mass. Plastics, as a whole, make up 18% of waste by volume and 7% by weight (plastic bags themselves are light and take up very little space). If plastic were to be replaced by other materials, trash weight would increase by 150%, packaging would weigh 300% more and energy consumed by the industry would increase by 100%.
Then again, plastic bags are a significant source of litter all over the world. Unlike a paper bag, that will biodegrade quickly when exposed to the elements, the lowly plastic bag will simply soar with the wind until it becomes entangled in a tree or dangles from a shrub in your flower bed. Nice.
The Origin of Paper Bags:
Paper comes from trees – and lots of them.
The paper grocery bag is an American innovation and was designed in 1883. It’s made from kraft paper – the word ‘kraft’ coming from the German language meaning ’strong’. Kraft paper is known for its strength and course texture. It’s strength lends to its reusability.
According to the American Forest & Paper Association, 2007 marked an all-time high of 56% for the recycling of paper consumed in the U.S. Curbside paper collection is easy and readily available in most parts of the country. While I applaud the consumer and the industry for reaching this goal and beyond (the industries goal is 60% by 2012) I’d like to point out that the manufacturing of paper products, like plastic, consumes natural resources and creates pollution. As a matter of fact, the production of a paper bag consumes 1 gallon of water (yep, per bag) equating to 50 times that of plastic bags. Yikes!
How does a paper bag get from forest to grocery store? Trees are found, marked and felled. Machinery is then used to remove the logs from the forest floor – whether by logging or, in more remote areas, helicopters.
Machinery requires fossil fuels and roads (which destroy habitat) thereby creating stress on the forests’ inhabitants (even logging a small area has a large impact on the entire ecological chain in surrounding areas).
Trees must dry at least three years before they can be used to make paper. Once aged, machinery is used to strip the bark, which is then chipped into 1 inch squares and cooked under tremendous heat and pressure. This wood stew is then ‘digested’ with a limestone and sulfurous acid for eight hours. The steam and moisture is vented to the outside atmosphere, and the original wood becomes pulp. It takes approximately three tons of wood chips to make one ton of pulp.
The pulp is then washed and bleached, both stages requiring thousands of gallons of clean water. Coloring is added to more water, and is then combined in a ratio of 1 part pulp to 400 parts water to make paper. The pulp/water mixture is dumped onto a web of bronze wires, the water showers through, leaving the pulp to dry. This final product is then rolled into paper.
Whew! What a lot of resources to just make the paper. We must include all of the chemicals, electricity, and fossil fuels used in the shipment of this raw material and in the production and shipment of a finished paper bag.
Where does a paper bag end its useful life?
Paper, when thrown away, can either be recycled or end up in the landfill. If it finds its way to the landfill, over time (and usually many, many, many years) it will break down into organic material. Paper bags can also be recycled in your yard (used as an effective weed barrier under top soil) and it will break down much faster. If it’s lucky enough to be recycled, the following process occurs:
The paper must be returned to pulp. This is done by the use of several different chemicals including sodium hydroxide, hydrogen peroxide, and sodium silicate. These chemicals bleach and spread out the pulp fibers. These fibers are then run through cleaning and screening sequences that remove any contaminants. The pulp must then be washed with clean water to remove ink particles that were removed from the paper by the chemical process. Flotation is a common way to remove ink. The pulp is submerged in clean water and heated. The ink attaches to air bubbles, which must then be removed before they break and let the ink float back to the pulp.
Most recycling centers treat the water they use to remove contaminants. Screens and mechanical cleaners are the typical methods used. Another, more environmentally friendly method is called ’sludge handling’. Sludge is composed of water, inks, pigments and small particles of waste. The materials are separated and cleaned. By including this process, it reduces any waste that may have to be taken to the landfill. These waste materials can be used in bricks, fertilizers and other useful products.
Other uses for paper bags:
A well-packed, single, grocery-size paper bag can hold the same volume of loot as 4 plastic bags. They hold a lot. Reuse them as trash can liners, book covers, or other craft projects. They also make great weed barriers (put down over weeds and cover with mulch) and eventually break down and naturally compost. Did you know paper bags can be composted (provided they don’t have a lot of printing on them)? Throw them straight into the compost pile (tear into small pieces for best results) or fill with yard green waste and toss straight into your compost pile.
Both paper and plastic bags consume large amounts of natural resources and the majority will eventually end up in the landfill. Both bags can be recycled to some extent and can be utilized around the house. I’ve read several studies comparing the two choices and none of them agree. Some feel plastic is the better overall choice, others paper. It’s really tough to say. Paper may consume more resources to produce, however, it is also more recyclable than plastic if you include the fact that paper can be composted and plastic bags cannot.
In my opinion, neither one is the winner. the best choice overall is to use a reusable bag. Many are made from recycled materials such as the new ChicoBag rePETe bag or natural materials such as our cotton string bags. Depending on the style, they’ll hold from 25-40lbs and last for years.
Most can be machine washed and can be kept in the car, glove compartment, purse or backpack. If your local supermarket gives you 5 cents a bag every time you use it, and you buy groceries once a week, it’ll pay for itself in about a year and a half. Most bags last for 3-10 years and beyond (I still have my original string bags that are over 10 years old and going strong). Many countries around the globe and many cities here in the US are banning the use of plastic bags at checkout or are charging for them. This makes the adoption of reusable bags are an even smarter choice.
Taking all the above information into consideration, feel confident that you’re making an informed decision the next time you’re at the grocery store. The most important thing to remember is to utilize every possible use for both the plastic and paper bags you do end up with to lengthen their life and minimize the impact on both the environment and our natural resources.