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Industry Viewpoint: Life cycle analysis of plastic vs. paper

By
Robert M. Lilienfeld, vice president of BioLogiQ

Sustainability seems simple, doesn’t it? Just get people to recycle more stuff, and we’ll be on our way to reducing pollution, greenhouse gas generation, and trash going to landfills.

Unfortunately, the reality is a bit different. Recycling has a significant role to play in our environmental efforts, but it isn’t always the best way to prevent or alleviate major environmental concerns.

A Brief History of Recycling
Recycling as we know it initially came into existence as a lower cost alternative to using materials made from natural resources that were expensive to purchase and/or process. Such products included newspapers, cardboard, and steel or aluminum cans. These items are resource and energy intensive to constantly produce from raw materials such as wood, iron ore, or bauxite.

Much of this recycling activity was started during World War II, as a way to ensure a steady supply of materials for the war effort. Since rubber for military vehicles was considered to be of strategic importance, used tires were also frequently collected for recycling, as a hedge against possible shortages of virgin rubber from Asian plantations that might come under Japanese control.

It’s interesting to note that glass was not initially part of the recycling stream, as it was generally used to produce reusable containers that were collected, washed, and refilled. Since glass is extremely heavy, the costs of collecting it for recycling is prohibitive: For reference, unless collection occurs near a smelting facility (usually within 50 miles), the energy cost of hauling such heavy loads generally outweighs the benefits of doing so.

After the war ended, a number of trends affected the typical American’s way of life, and brought about profound changes in the ways in which people purchased and consumed groceries and other goods:

• The automobile and newly created national highway system, along with the postwar baby boom, led to the rise of suburban living, commuting, and demands for more convenient products and services.

• Supermarkets such as A&P replaced general stores, leading to an enormous increase in consumer choice, reduced pricing, and more convenient packaging that was easily disposed of by simply tossing into the trash.

• The growth of mass media, via radio and television, enhanced awareness, interest and demand for both consumables and durable goods.

This demand for ever lower-cost products also led to the proliferation of paper and plastic packaging that delivered more goods per unit of material; did so more conveniently (open and toss); and was less costly than metal or reusable glass containers. As this proliferation grew in the 1960s and 70s, the perceived garbage crisis spawned by increases in categories such as construction debris (suburban home building), disposable packaging, and yard waste (suburban grass clippings and leaves) led people to believe that America was running out of landfill space.

The solution? Start recycling more packaging, especially plastics!

chartThe Value of Recycling
Is recycling truly the primary solution to our waste reduction needs, as many people expect? Let’s start with the Environmental Protection Agency the federal agency responsible for ensuring a sustainable society. As you’re probably aware, the EPA is responsible for the concept of The three Rs: “reduce, reuse, recycle”.

The more technical name for “The 3Rs” is the non-hazardous materials and waste management hierarchy. As stated on the EPA website, the hierarchy was developed “in recognition that no single waste management approach is suitable for managing all materials and waste streams in all circumstances.”

The hierarchy ranks the various waste management strategies from most to least environmentally preferred. It emphasizes reducing, reusing, and recycling, in that order, as the key to minimizing waste and maximizing sustainability.

As shown above, recycling is in the second tier of preferred solutions, just below reducing and reusing. There are three strong reasons for this:

• Source reduction, which is the minimization of material and energy usage, is always the smartest thing to do, since it generates more value with less resource use. Put simply, it’s better to not create waste than to figure out what to do with it.

• Recycling is a process like any other, requiring energy usage to collect, store, sort, process, and remanufacture products and packages. This is a key reason that home recycling programs are most successful in areas of high population density: The energy cost of driving recycling trucks among far apart houses in rural areas offsets the value of the materials being collected.

• The consumption of products continues to grow, regardless of recycling activities. It’s generally recognized that at least 90% of the environmental impact created by consumer goods is caused by products, and only 10% by their packaging. Thus, reducing consumption – a form of source reduction – has far greater benefit in the reduction of material, energy, and water use, along with generation of greenhouse gases and other pollutants.

Thus, for all its benefits, recycling by itself cannot, and was never intended to prevent or remediate, major environmental concerns such as climate change, habitat destruction, and loss of biodiversity. Its primary roles are the reduction of solid waste sent to landfills and minimizing the use of virgin resources.

Recycling and Climate Change
Of the major environmental concerns, climate change is generally considered as needing the greatest global emphasis. Both the G7 in its latest Leadership Recommendations, and The World Economic Forum recognize it as our most pressing environmental challenge.

These and most other scientifically aware governmental, non-profit, and business organizations recognize that the most effective way to mitigate climate change is by reducing greenhouse gas generation, primarily carbon dioxide. Reducing our “carbon footprint” is thus considered to be the most important strategy in the fight to mitigate global climate change.

Are recycled or recyclable products more likely to reduce greenhouse gas generation, and therefore to be better job or remediating climate change than their non-recycled counterparts? Let’s look at a few examples.

Example 1: Virgin vs. Recycled Plastic
A life cycle study performed by Franklin Associates for the National Association for PET Container Resources (NAPCOR) indicates that the use of recycled PET (RPET) resins can reduce greenhouse gas generation vs. the use of virgin resin by 60 percent (Plastics Recycling Update, Nov. 11, 2020).

To be more specific, NAPCOR stated that, “A reduction of 60 percent in greenhouse gas emissions may be achieved by replacing a unit of [virgin] PET with RPET,” NAPCOR stated in a release. “When using RPET in place of [virgin] PET, a 75 percent lower total energy demand may be achieved, and 40 percent less process and transportation energy is expended.”

For reference, PET is one of two plastics that is commonly recycled. It’s the primary plastic used in beverage bottles, specifically soft drink and water containers. There are two reasons for its recycling popularity: First, there’s a lot of it used. Second, as discussed above, it is far more efficient, environmentally and economically, to make new bottles from recycled PET than from virgin PET.

Example 2: Plastic Closures vs. Cardboard Closures
In the example above, we did an “apples to apples” comparison of the same plastic, PET, in two forms: virgin and recycled. We learned that use of the latter significantly reduces CO2 emissions.

What happens when we compare different materials that are used to make the same product? We decided to examine the humble bread bag closure, made by a company called Kwik Lok. (Note: I recently wrote a story in Plastics Today about this company’s new product called Eco-Lok, which is made from both traditional plastic and a plastic made from natural and renewable ingredients that include starch and glycerine.)

The little Kwik Lok closure you see on bread and produce bags is made from polystyrene, a plastic that is not readily recycled, and is therefore not considered to be recyclable by consumers. Styrene is derived from a non-renewable fossil fuel.

The company makes a similar product out of cardboard that contains recycled material. (And, while it is also technically recyclable, we doubt that many of them are recycled, given their small size and lack of recycling notification). This cardboard closure is also made from renewable resources such as wood or fiber.

chart

Which is more sustainable from the key perspective of greenhouse gas generation? Plastic closures weigh a bit more than the cardboard ones (6.5 percent to be reasonably exact). But they produce 92 percent less greenhouse gas emissions! What’s more, this is true even though the plastic closures contain no recycled content, while the cardboard ones do contain recycled material, generally up to around 25-35 percent.

Discussion
Versus cardboard closures, how can the plastic versions weigh more, be made solely from virgin material, be produced from non-renewable resources, and still generate over 90 percent fewer greenhouse gas emissions? The answer is actually quite simple: It takes much less energy to produce closures from polystyrene than from cardboard, and greenhouse gas generation is a byproduct of energy use.

It’s also important to note that different plastics have different energy profiles. The PS used in closures is a much simpler and more efficient polymer to produce than the PET used in beverage bottles. (See Journal of Cleaner Production, Volume 17, Issue 13, September 2009, pages 1183-1194.) Differences in energy efficiency can significantly change the environmental footprint of the packaging in which various materials are used.

In fact, the production efficiency and the strength of plastics versus other materials are the key reasons why plastics began replacing other materials in the 1950s and 60s. The key metric is called the strength to weight ratio, and it measures how much weight a material can support in various forms – sheets, films, etc. As an analogy, plastics are the ants of the packaging world – light but extremely strong, with the ability to support far more mass than they themselves weigh.

To get a better feel for the value of the strength of a material compared to its weight, consider a 5 oz. portion of tuna sold in either a can or a flexible pouch. A can weighs 30 grams, and has a 71 percent recycling rate. A pouch weighs six grams and is not recycled. Yet, even when accounting for the vast difference in the recycling rate, the pouch produces 30 percent less waste!

Key Conclusion
While recycling/recyclability and use of renewable resources are important strategies in the effort to reduce the carbon footprint of packaging, the most effective strategy is to use the material that generates the least amount of carbon dioxide during its lifecycle of harvesting (or extraction), production, use, diversion, and disposal. Depending on where, when, and how energy is used, that material can be virgin, recycled, or some combination of both. The science of life cycle analysis is the clearest way to make this determination.

I made this same point in a 1995 New York Times Op-Ed piece written with Dr. William Rathje. It’s as relevant today as it was 25 years ago:

“…we must be less willing to accept glib, ideological pronouncements of right and wrong, good and evil, cause and effect. To truly change the world for the better, we need more facts, not simply more faith.”

Robert (Bob) Lilienfeld has been involved in sustainable packaging for 25 years, working as a marketing consultant, editor, writer, and communications expert. He is a regular contributor to a number of packaging and environmental magazines and journals. Lilienfeld ’s personal website is https://www.robertlilienfeld.com/.

 

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