Which Shopping Bag is Best Nowsaday?

While each type of bag has its pros and cons, the best option from an environmental standpoint is bags are generally considered if they are reused multiple times. However, it's important to note that the most sustainable choice is to reduce overall bag consumption by using reusable bags and promoting responsible consumption habits. Additionally, choosing bags made from recycled materials or other sustainable alternatives like jute or hemp can also contribute to a more eco-friendly approach.

Comparing the bag choices—plastic, paper, cotton, and PP woven shopping bag

On March 1 in 2020, New York State instituted its plastic bag ban, joining seven other states in an attempt to lessen litter, garbage in landfills, ocean pollution, and harm to marine life. March 1 was also the day that New York acknowledged its first coronavirus case. And despite the fact that California was the first state to ban plastic bags in 2014, San Francisco has reversed its plastic bag ban because of the coronavirus, outlawing the use of reusable shopping bags, which are capable of spreading viral and bacterial diseases. New Hampshire, Massachusetts, Oregon, and Maine have also banned reusable bags or delayed their plastic bag bans for now as have a number of cities.

Given the concerns pulling us in different directions—our health, the environment, climate change—what’s an environmentally responsible, health-conscious shopper to do? Let’s compare the main bag choices—plastic, paper, cotton, and PP woven shopping bag —to try to answer that question.

Life Cycle Analysis of Plastic, paper, cotton, and PP woven shopping bag

To understand the full spectrum of impacts and benefits of a particular bag, we need to analyze its life cycle. A life cycle analysis (LCA) looks at how much energy is used and how many environmental impacts a product is responsible for at every stage of its life, from cradle to grave. This includes extracting the raw materials, refining them, manufacturing the product, packaging it for shipment, transporting and distributing it, its use and possible reuse, recycling, and final disposal.

Plastic bags

Plastic bags were invented in 1967, but only became widely used in stores in the 1970s. The most commonly found thin plastic shopping bags given out at cash registers are usually made of high-density polyethylene (HDPE), but some are made of low-density polyethylene plastic (LDPE).

The energy embodied in plastic bags comes initially from the mining of the raw materials needed to make them—natural gas and petroleum—whose extraction requires a lot of energy. The raw materials must then be refined, which requires yet more energy. Once at a processing facility, the raw materials are treated and undergo polymerization to create the building blocks of plastic. These tiny granules of polyethylene resin can be mixed with recycled polyethylene chips. They are then transported by truck, train, or ship to facilities where, under high heat, an extruder shapes the plastic into a thin film. The film is flattened, then cut into pieces. Next, it is sent to manufacturers to be made into bags. The plastic bags are then packaged and transported around the world to vendors. While polyethylene can be reprocessed and used to make new plastic bags, most plastic bags are only used once or twice before they end up being incinerated or discarded in landfills. The Wall Street Journal estimated that Americans use and dispose of 100 billion plastic bags each year, and the EPA found that less than five percent are recycled.

A 2014 study done for the Progressive Bag Alliance, which represents the U.S. plastic bag manufacturing and recycling industry, compared grocery bags made from polyethylene (HDPE), compostable plastic, and paper with 30 percent recycled fibers. It found that the HDPE bags ultimately used less fuel and water, and produced less greenhouse gas gases, acid rain emissions, and solid waste than the other two. The study, which did not consider litter, was peer-reviewed by Michael Overcash, then a professor of chemical engineering at North Carolina State University. Because the carrying capacity of a plastic and a paper bag is not the same, the study used the carrying capacity of 1,000 paper bags as its baseline and compared their impacts to the impacts of 1,500 plastic bags. The plastic bags used 14.9kg of fossil fuels for manufacturing compared to 23.2kg for paper bags. Plastic bags produced 7kg of municipal solid waste compared to 33.9kg of paper, and greenhouse gas emissions were equivalent to 0.04 tons of CO2 compared to paper’s 0.08 tons. Plastic bags used 58 gallons of fresh water, while paper used 1,004 gallons. Energy use totaled 763 megajoules for plastic, and 2,622 megajoules for paper.

Sulfur dioxide, a type of sulfur oxide, and nitrogen oxide emitted from coal-fired power plants that produce the energy for processing bags contribute to acid rain. The plastic bag produced 50.5 grams of sulfur oxides compared to 579 grams for the paper bag; and 45.4 grams of nitrogen oxides, compared to 264 grams for paper.

Non-woven polypropylene bag

Non-woven polypropylene cloth-like plastic totes that are often given away free as publicity are stronger and more durable than HDPE and LDPE plastic bags, and thus can be used multiple times. Non-woven polypropylene (PP) bags are a type of reusable bag made from spun bonded polypropylene fibers. These bags are commonly used as an alternative to plastic bags and are often referred to as reusable tote bags or non-woven bags. Here are some key points about non-woven polypropylene bags:

They are made from polypropylene polymers derived from fossil fuels and can include recycled material. The polymers are spun into threads and then pressed together between heated rollers to produce a fabric that feels similar to canvas. According to a California State University, Chico study, if comparing one-time use, non-woven polypropylene bags use considerably more non-renewable energy and freshwater than single-use plastic bags. Moreover, they are not biodegradable and need to be washed to avoid contamination—COVID-19 has been found to survive on polypropylene for three days.

Paper bags

Paper bags are biodegradable and renewable, as they are made from trees. They are recyclable and can be composted under certain conditions. However, their production requires energy, water, and chemicals, and deforestation for paper production can have adverse ecological effects. Paper bags are generally more durable than plastic bags, but they are less resistant to water and tearing.

Paper bags are made from renewable resources and are biodegradable. In the U.S., over 10 billion paper bags are consumed each year.

Cotton totes

Cotton bags are made from a renewable resource and are biodegradable Cotton bags, often referred to as reusable or tote bags, are made from natural fibers and can be reused multiple times. They are biodegradable and have a lower environmental impact compared to plastic and paper bags. However, cotton production requires large amounts of water, pesticides, and energy. The overall environmental benefits of cotton bags depend on how many times they are reused. If used extensively, cotton bags can be a more sustainable option.

Cotton first needs to be harvested, then cotton bolls go through the ginning process, which separates the cotton from stems and leaves. Only 33 percent of the harvested cotton is usable. The cotton is then baled and shipped to cotton mills to be fluffed up, cleaned, flattened, and spun. The cotton threads are woven into the fabric, which then undergoes a chemical washing process and bleaching, after which it can also be dyed and printed. Spinning, weaving and other manufacturing processes are energy intensive. Washing, bleaching, dyeing, printing, and other processes use large amounts of water and electricity.

Today, another critical factor to consider is that cotton and other reusable shopping bags can carry bacteria and transfer it from home to grocery carts and checkouts and back again. One study of reusable bags discovered that they were rarely washed and as a result, bacteria were found in almost all the bags studied, with 12 percent containing E. coli. While most reusable bags are made of polypropylene, upon which COVID-19 has been shown to survive three days, so far there are no scientific findings about how long the coronavirus can survive on clothing or textiles. However, in a 2005 study of the SARS virus, another coronavirus, it survived on cotton for five minutes to one hour depending on the amount of exposure.

To be safe, wash reusable bags in warm or hot water after shopping, which can reduce the bacteria by 99.9 percent and kill COVID-19. Only use the bags for groceries and ideally, put meats into a separate bag since meat juices left in bags can enable bacteria to grow quickly. Don’t leave reusable bags in the car because when it gets hot, bags become an ideal place for bacteria to grow.

The final outcome

Generally speaking, bags that are intended to last longer are made of heavier materials, so they use more resources in production and therefore have greater environmental impacts. To equal the relatively low global warming impact of plastic bags, paper, and cotton bags need to be used many times; however, it’s unlikely that either could survive long enough to be reused enough times to equal the plastic bag’s lower impact.

Ultimately, the single use of any bag is the worst possible choice. The key to reducing your environmental impact is to use whatever bags you have around the house as many times and in as many ways as possible. It’s understandable if, during this time of COVID-19, you’ve reverted to plastic bags to protect yourself and are probably discarding them after one-time use. But when the risk of COVID-19 abates, remember to try to use whatever bag you choose as many times as possible. HDPE or LDPE bags can be used to store food, line wastebaskets, pick up dog poop, pack lunches, pad packages, stash wet umbrellas, and many more ways.

Cohen believes that the important issue isn’t so much the specific environmental impact of the packaging you use, however, but what it is doing to your behavior pattern. “What’s key is to get people conscious of packaging and to start thinking about closing the loop from production to consumption,” Focusing solely on the specific environmental impact of the packaging material is important, but it's equally crucial to consider the entire lifecycle of the product, from production to consumption and disposal.

By fostering environmentally conscious consumer behaviors, we can collectively work towards closing the loop in the production and consumption cycle. This involves considering not only the specific form of packaging but also the entire life cycle and the associated environmental impacts.

TLPPACKAGING FOR SHOPPING BAGS