According to a study conducted by the U.S. EPA, “plastic bags use 40% less energy to produce and generate 80% less solid waste than paper. In addition, recycling a pound of plastic consumes 91% less energy compared to a pound of paper. One of the main advantages of plastic bags is that, compared to other types of shopping bags, their production involves the lowest environmental cost.
Thin plastic grocery store bags are usually made of high-density polyethylene (HDPE).). Although the production of these bags uses resources such as oil, it produces less carbon emissions, waste and harmful by-products than the production of cotton or paper bags. Plastic bags are also relatively sturdy and reusable. Many of the studies on the different packaging options that show that the production of plastic bags requires fewer resources assume that plastic bags are used at least twice when arriving home and once as a garbage bag, and they take this fact into account when calculating which bags are more sustainable.
In terms of disposal, paper bags are better than plastic bags. If you have access to the compost, simply break it up and throw it away. Or if, like me, you've grown moldy pots in your kitchen too many times and now you're a little scared of composting compost, recycling is the next best option. As long as they are not too contaminated with food, paper bags can go to any municipal recycling bin. In addition to varying greatly in terms of their compatibility with the environment, there is the possibility that reusable bags will not be used, because consumers must remember to take them with them to the store.
Reputation aside, single-use plastic bags have the lowest carbon footprint, at least in terms of producing individual bags. According to the study, a single cotton bag requires “between 100 and 2,954 uses for its environmental impact to be equivalent to the environmental impact of a conventional plastic bag. To have a comparable environmental footprint (encompassing climate change and other environmental effects) to that of plastic bags, a cotton bag may have to be used thousands of times. This is because plastic bags, like all plastic materials, eventually break into microscopic pieces, which scientists refer to as microplastics. According to a study, three reuses of a paper bag are needed to neutralize its environmental impact, in relation to plastic.
Made from a more durable type of plastic, these bags must be reused about eleven times to reach the point of balance with the impact of conventional plastic. Regardless of whether the bag is made of plastic, paper or another material, the most sustainable option is the bag you already have. Reusable bags made of non-woven polypropylene plastic are also common and, in fact, their production consumes less carbon. In general, it's essential to make the effort to reuse any bag you have in your possession and to dispose of it responsibly.
This isn't realistic, as many people forget their bags at home, meaning the bags aren't reused as much as you might think. Recycling plastic bags is a difficult task; they fly around the recycling plant and get stuck in the machinery. In Canada, Recyc-Québec, an environmental organization based in Montreal, published a study that found that the conventional plastic bag is the best option for the environment because of several advantages. Some large grocery stores offer on-site plastic bag recycling options (look for a recycling center near you).
Reusable bags can be made of many different materials (hemp fiber, for example, is especially good for people who consider themselves modern), but the two most common types are cotton and nonwoven polypropylene (PP), a more durable type of plastic.
