Plastic bags: Your cost vs. your impact

Consumers who make the switch to reusable bags are not entirely off the hook — fabric, paper, and reusable plastic have a carbon footprint, too.

If Suffolk County stores had a nickel for every time a customer used a plastic bag — actually, now they do.

Jan. 1 marked the start of Suffolk County’s new 5-cent bag fee, a law requiring stores to charge customers for disposable bags, including plastic and paper. Lawmakers and supporters said they’re trying to minimize waste.

But what would it cost consumers to keep using plastic bags?

Calculate your cost

Enter the number of plastic bags you use during a normal week.

In a year, you’ll spend $26.00 on grocery bags

You’ll use 520 grocery bags

Of course, it’s that sheer number of grocery bags used — and their impact on the environment — that pushed lawmakers to institute the fee.

But even consumers who make the switch to reusable are not entirely off the hook. Reusable bags, including fabric, paper, and plastic, have a carbon footprint, too.

Here’s a snapshot of your own annual environmental impact if you use plastic vs. reusable:

These calculations are based on a 2014 study by Clemson University’s Center for Flexible Packaging taking into account the whole lifecycle of the bag, from manufacturing to shipping and disposal. The study found that shoppers used about seven reusable bags for every 10 plastic bags per trip. Your impact will vary depending on which kind and how many reusable bags you actually use. The calculations below assume you can reuse your non-plastic bags all year.

If you are using plastic bags per week, you will need 520

If you are using reusable bags, you will need 7

Emissions

Using 520 plastic bags will create emissions equal to burning 13.43 pounds of coal (12.27 kg CO2)

Using 7 reusable bags will create emissions equal to burning 3.10 pounds of coal (2.83 kg CO2)

Water

Using 520 plastic bags will require 5.77 gallons of water

Using 7 reusable bags will require 10.02 gallons of water

Fossil Fuels

Using 520 plastic bags will require the same amount of fossil fuels as driving 52.99 miles (7.32 kg oil)

Using 7 reusable bags will require the same amount of fossil fuels as driving 8.39 miles (1.16 kg oil)

The analysis from Clemson University focused on polyethylene bags with no recycled content and reusable non-woven polypropylene bags. The study estimated shoppers would need to use their reusable bags at least 22 times to lessen their environmental impact. They found the impact on water usage was particularly high for the reusable bags sold at most grocery stores because of the water used to grow and process the cotton used in the bag’s stitching.

The Clemson research was funded by plastic bag manufacturer Hilex Poly and conducted by packaging science faculty in the Center for Flexible Packaging and was peer reviewed. Its findings line up with those of similar assessments, including a widely-cited study by the United Kingdom’s Environment Agency. The UK study was cited in a recent report from the New York State Plastic Bag Task Force.

Sources: Clemson University; U.S. Environmental Protection Agency; Citizens Campaign for the Environment; New York State Department of Environmental Conservation.

Comments