To Bag or not to Bag? And which Bag?

''Would you like a bag for that?'', is the question we've all been asked a gazillion times throughout our consumer lives.

And, admit it or not, many times we’ve gone for the yes option because we didn’t have one on hand. However, recent years brought a change of trend, and the ongoing ecological downward spiral we live in, made us stop in our tracks and rethink our lifestyle choices. We are becoming more conscientious, trying to reduce our environmental impact by refusing plastic bags, opting for paper ones or proudly wearing our cotton totes.

But are paper and tote bags really a better choice? Are biodegradable bags biodegradable? Who is the real winner in the reusable bags vs plastic bags fight?

To answer these questions and understand the benefits and impacts of a particular type of bag, we need to look at its life cycle analysis (LCA). LCA examines how much energy is used and how many environmental impacts a bag is responsible for at every stage of its life.

So let’s get to it, one bag at a time.


Plastic bags and their environmental impact

The most common plastic bags are usually made of high-density polyethylene (HDPE) or low- density polyethylene (LDPE) and by now, they have earned a bad rep all over the world. The horror pictures of marine life suffocating in them, tree branches entangled with them, landlines filled with them are imprinted in our brains and we now consider them a modern menace.

Reputation aside, in terms of single-bag production, single-use plastic bags carry the lowest environmental impact: its production results in less carbon emission, waste and harmful by products.

It was concluded in a 2014 study which compared HDPE plastic bag, compostable, biodegradable plastic bag and paper bag with 30% recycled fibers, that the HDPE plastic bag used less resources and produced less greenhouse gases, acid rain emissions and solid waste than the other two. And a 2011 UK study compared bags made of HDPE, LDPE, non-woven polypropylene, a biopolymer made from a starch polyester, paper and cotton through nine categories (global warming potential, depletion of resources such as fossil fuels, acidification, eutrophication, human toxicity, fresh water toxicity, marine toxicity, terrestrial toxicity and smog creation). The results showed that HDPE bags had the lowest environmental impacts of the lightweight bags in eight of the nine categories because it was the lightest bag of the group.

Nevertheless, how we use and dispose of plastic bags matters even more. Single-use plastic bags are far from being single-use, they are sturdy enough to be reused repeatedly - the problem is that they aren’t due to bad consumer behavior. Plastic bags are recyclable, but they require special equipment for processing and cannot be mixed with general recycling. Because they are light they fly away in the recycling plant and get stuck in machinery. Bags that are not recycled become litter and they do not biodegrade – eventually, after a long period of time, they break down into microscopic pieces, known as microplastic, and continue doing harm to our water, air and food systems. And let’s not forget that production of these bags uses resources like petroleum, which is a finite source, and as it will become more difficult to obtain it, it will become more damaging for the environment.


Paper bags

Paper bags are made from renewable resource and are biodegradable.

However, when compared to plastic, making a paper bag emits 51% more greenhouse gasses, creates 50 times more water pollution, uses four times more raw materials and consumes two times more energy.

A portion of that impact results from them being 6 to 10 times heavier than plastic bags, which correlates to higher costs of transportation.

According to the previously mentioned 2011 UK study, it takes three reuses of a paper bag to neutralize its environmental impact when compared to plastic. Unfortunately, once used, paper bags are unlikely to be re-used since they tear easily and don’t hold up when wet. Paper bags can be recycled, but a limited amount of time, since the fibers weaken during the process.

On the plus side, paper bags are biodegradable and can be used for purposes like composting. They do need to be exposed to enough oxygen in order to biodegrade; otherwise, the process can take decades, making the landfill more of a long-term storage for paper than a mechanism for biodegrading.


Reusable bags vs plastic bags

Reusable bags are made from many different materials, most popular being cotton and nonwoven polypropylene (PP), so the environmental impact varies widely.

Cotton bags, for instance, are made from a renewable source and are biodegradable, but making them has a huge impact on the environment and according to studies, they would need to be used at least 131 times in order to break even with the plastic bag. Nonwoven polypropylene bags require fewer resources to be made, and need to be used 11 times to break even with the impact of conventional plastic. However, they are not biodegradable.

Another issue with reusable bags is the way people use them; they have them at home, but rarely with them when shopping which leads to buying another bag (of any kind).

Over the years, they have become so widely spread and cheaply accessible that it encourages consumers to see them as disposable, which defies their purpose.

Additionally, since tote bags became a trend years ago, there’s a tendency to collect them and use them as fashion staples, making the totes multiply just like plastic bags.



Many stores are now offering biodegradable bags as a more eco-friendly solution, as they are able to break down into harmless material faster than traditional plastic. Or so we think.

In a recent experiment, researchers collected samples of five different types of bags (HDPE bag, a biodegradable plastic bag made in part from oyster shells, two kinds of bags made from oxo-biodegradable plastic, compostable bag made from plant products) and placed them in four different types of environment (buried in garden soil, submerged in salt water, exposed to daylight and open air, sealed in a dark container in a temperature-controlled lab).

The results were fascinating:

  • Three years in marine environment wasn't enough time to break down any of the plastic, except for the plant-based compostable option, which did disappear underwater within three months
  • The plant-based compostable option, however, remained intact after 27 months in the ground
  • The only treatment that consistently broke down all of the bags was exposure to open air for more than nine months

Conclusively, even if these bags take less time to break down, they still become litter and endanger marine life. In theory, they’re green and meant to solve our problems, but in reality that’s not the case.


Where do we go from here?

After a mixed bag of information, choosing the right option might be difficult because it seems no choice is a good choice. On one hand plastic bag seem to have the lowest impact on the environment when considering their production. On the other hand, they are almost impossible to dispose of correctly and recycle. And tote bags seem not to be as eco-friendly as we thought. 

The simplest and most effective advice would be to use the bags you have, many times and avoid buying new ones.

The great thing about most of the mentioned bags is that they can be used repeatedly for shopping purposes and then reused: for instance, a worn out plastic bag can become a trash bag, or a poop-scoop bag and a paper bag can be used to pack lunch. Tote bag, often washed to avoid risk of developing bacteria, can be used countless times while at the same time displaying ones fashion sense.

The key to sustainability is longevity, so use the bags until the end of their life cycle. Put simply: reduce and reuse.


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