What’s With All Those Plastic Pouches at the Grocery Store?

Professor Plastics

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I conducted an experiment this weekend. Not in my lab at the university – at my local grocery store and at home in my kitchen.

I’m a big fan of fish protein in all forms: fresh, frozen, canned. As I walked down the canned food aisle in my grocery store, it struck me that “canned” fish is not sold solely in cans anymore. Tuna fish, for example, is also sold in flexible plastic pouches. I picked up one of these pouches and compared it to a can of tuna and thought: huh, this plastic pouch seems to weigh a bit less. So I put both in my shopping cart to examine at home.

As I walked up and down the aisles, I noticed that all sorts of other products typically sold in cans, jars, and boxes now are also packaged in pouches. Nuts, dried fruits, trail mix, ethnic foods, spices, sugar, flour, baby formula, chocolate, pet foods, and even wine and some alcoholic beverages are now packaged in lightweight, flexible plastic pouches.

In the refrigerator and freezer sections, there are more pouches (often re-sealable) for fish, chicken strips, dinner entrees, and more.

The Experiment

At home I grabbed my handy kitchen scale, removed the five ounces of tuna from the can and pouch, and then weighed each. The steel can: 35 grams. The plastic pouch: 10 grams.

Wow. The plastic pouch delivered the same amount of food with three and half times less packaging material. I already knew that these plastic pouches typically are lighter, but seeing the numbers on my kitchen scale really brought home (Ha! Brought home. Get it?) how lightweight plastics can deliver more food with less packaging.

Life Cycle Advantages

These pouches are just one example of how lightweight plastic packaging contributes to sustainability.

I wrote about this previously in an article that looks at the entire “life cycle” of six types of common packaging: caps and closures, beverage containers, other rigid containers, carrier (or shopping) bags, stretch/shrink wrap, and other flexible packaging. Recent studies in the U.S. and Europe found that replacing these lightweight plastics with alternatives would:

  • require 450 percent more material by weight – that’s equivalent to the weight of more 169,000 Boeing 747 jumbo jets;
  • require 80 percent more energy demand – on an annual basis, that’s equivalent to the energy from more than 91 oil supertankers;
  • result in 130 percent more global warming potential impacts – that’s equivalent to adding 15.7 million more cars to our roads each year.

So in a nutshell: lightweight plastic packaging – such as these new pouches – delivers more goods with significantly less waste, energy use, and global warming potential.

But What About Recycling?

Many people assume that packaging must be recyclable to be “sustainable.” Recycling certainly does help reduce the environmental impact of packaging. Recycling extends the life of valuable materials, reduces energy use, and cuts greenhouse gas emissions – the equivalent of removing 28 million cars from the road in one year in the case of paper recycling (according to the U.S. EPA). Plus, recycling industries create significantly more jobs than simply hauling and burying garbage. Simply put, when materials have value, burying them in a big hole in the ground is an egregious waste of resources.

But… let’s take a look at the tuna fish example. The plastic pouch uses much less material than the metal can. Then look at life cycle figures again. Alternatives to plastic packaging use much more material, use much more energy, and result in many more greenhouse gas emissions. One way to envision this: just think about how much more fuel is used to haul food across this country when packaged in heavier containers.

And even though most of these pouches are not collected in community recycling programs, they can still produce less waste than packaging that is recycled. A 2008 life cycle study looked at 10 ounces of tuna sold in a steel can versus a plastic pouch — the study found that the can produces nearly four and a half times as much post-consumer waste as the pouch, even though nearly two thirds of the steel cans are recycled. Why? “The pouch systems are light-weight and so produce less post-consumer solid waste,” according to the report.

I’m a big fan of plastics recycling (in addition to fish protein!) and have watched recycling rates grow year after year. But I’m also a big fan of how plastics contribute to sustainability… beyond and in addition to recycling. As I’ve said previously, looking only at recycling when reviewing the sustainability of packaging is sort of like choosing a spouse based solely on good looks – there’s lots more to consider.

Energy Recovery

In addition to recycling, some communities are recovering energy from non-recycled materials. And that’s where plastic pouches can shine again. The molecules that make up plastic pouches and other plastic packaging are a powerful source of energy. Non-recycled plastics can supply more than 15,000 BTUs per pound in a facility that converts waste to energy. That’s more energy per pound than any type of coal. And plastics have a higher energy value than other non-recycled materials, as well, so they help increase the efficiency of producing energy at waste-to-energy facilities.

So, to recap. Lightweight plastic pouches use less material. They require less energy to create. They move food with greater fuel-efficiency from the farm to the family table. They result in fewer greenhouse gas emissions. And where waste-to-energy facilities exist, they can provide energy to power our homes.

That’s quite a package.

Check out this video series with “Ace of Cakes” Duff Goldman who shows how he reduces food waste and packaging waste in his kitchen – with a little help from plastics.