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Identifying the most sustainable packaging for a product is rarely a simple exercise.
Today, everyone wants sustainable packaging. Unfortunately, what's perceived as sustainable may not be the most environmentally friendly choice. Application and geographic location influence the environmental impact of the final package because of variability in the amount and combination of materials used, the availability of raw materials, postconsumer collection and recycling resources, and other factors.
In addition to exerting minimal environmental impact, sustainable packaging also must be cost-competitive and functional, according to the Sustainable Packaging Coalition.
It's no wonder that "packaging people are unsure what sustainable packaging is," says Patricia Enneking, director of global sustainability and environmental affairs at Klöckner Pentaplast Group (Gordonsville, VA). Klöckner makes polyvinyl chloride, polyester, and polylactide film and sheet, laminations, and barrier-coated structures used in packaging. "It's perception versus reality," Enneking explains. People think that if a package is one of the following—recyclable, biodegradable or compostable, derived from a renewable source, or contains recycled content—it's sustainable, but focusing on a single feature may not necessarily result in the best package for the environment.
What does consistently result in improved sustainability is weight reduction. Thus, a good rule of thumb is to maximize the product-to-package ratio. Reducing package weight conserves raw materials and energy and reduces discards and greenhouse gas (GHG) emissions. It also lowers freight costs throughout the supply chain.
In fact, weight is such a significant environmental attribute that a lightweight package that isn't recycled may have an advantage over a heavier package with a high recycling rate. For example, the 2007 Packaging Efficiency Study published by the ULS Report shows that coffee drinkers send more pounds of coffee cans than of coffee pouches to the landfill, even though steel coffee cans are recycled at a relatively high rate in the US and pouch packaging is virtually never recycled.
Wal-Mart Stores is widely credited with jumpstarting the thinking on sustainable packaging when it set a goal to cut waste generation to zero by 2025. Its Packaging Scorecard, introduced in November 2006 and implemented in February 2008, requires suppliers to look at their packaging holistically by ranking it according to several criteria such as GHG or carbon-dioxide generation per ton of production, product–package ratio, cube utilization, recycled content, and recovery value.
Table I: US recycling rates for common packaging materials.
The Sustainable Packaging Coalition also advocates looking at the big picture. According to its definition, sustainable packaging has the following characteristics:
Is a recyclable package better than a nonrecyclable package? Maybe. As noted in the coffee-can example, extremely lightweight, nonrecyclable packaging may send less waste to the landfill. Drugmakers should consider a material's recycling rate and recycling infrastructure. If a recyclable package isn't actually collected and recycled, it will have just as much negative impact on the environment as a nonrecyclable package, perhaps more.
Is it better to create packaging from renewable resources than from nonrenewable sources? Packaging derived from renewable resources such as trees and other plants slows the depletion of nonrenewable resources such as oil, steel, and aluminum. However, making packaging from food plants such as corn is not a sustainable practice if it reduces the food available for people or increases its cost.
In addition, although the recycling infrastructure for fiber-based packaging such as paper and corrugated boxes is well established and those materials are recycled at a relatively high rate, recycling for biopolymers is virtually nonexistent. Even worse, the presence of biopolymers may contaminate the recycling stream of conventional polymers. Polylactide, for example, ruins recycled polyethylene terephthalate (RPET) at levels of less than one bottle per thousand, according to a study by PTI-Europe (Yverdon-les-Bains, Switzerland) for the Technical Committee of Petcore.
In defense of PVC
However, it may be possible to obtain traditional polymers from renewable resources, which would be the best of both worlds. A joint venture is building a facility in Brazil to produce linear-low-density polyethylene from sugarcane-derived ethanol. The resulting resin, scheduled to be available in 2011, will be molecularly and functionally equivalent to traditional hydrocarbon-based linear-low-density polyethylene (Dow Chemical, Midland, MI, and Crystalsev, São Paulo, Brazil).
Hybrid resins that combine petroleum content with renewable content also are appearing on the market. One polypropylene made of equal amounts of petroleum and starch injection molds, extrusion blowmolds, and thermoforms just like purely petroleum-based resin (Biopropylene, Cereplast, Hawthorne, CA).
Are biodegradable materials better than nonbiodegradable materials? Not if they end up in a landfill. Modern landfills are designed to prevent decomposition. Thus, "biodegradable material in a landfill is of questionable value," says Enneking. Even worse, biomaterials that do degrade generate methane, a GHG with 23 times more heat-trapping power than carbon dioxide. According to the Environmental Paper Network, more than one-third of municipal solid waste is paper, and municipal landfills represent the largest source of human-related methane emissions. In fact, the US Environmental Protection Agency has identified the decomposition of paper as among the most significant sources of landfill methane.
Are compostable materials better than biodegradable materials? Compostable materials are biodegradable, but not all biodegradable materials are compostable. Compostable materials decompose in commercial or home composting facilities in a matter of weeks without any negative impact. To ensure compostable packaging performs as expected, it should meet US or European standards for degradability in industrial composting settings (i.e., ASTM D6400 or EN 13432, respectively) or be certified by the Biodegradable Products Institute. Yet the extremely limited access to commercial or home composting facilities means that few compostable packages are actually being composted at present.
Is packaging that contains recycled content better than that made of virgin material? Recycled content will significantly reduce costs and GHG emissions for packages made of aluminum, glass, and steel. In addition, these materials can be recycled repeatedly with no loss in properties.
Infinite reuse of fiber- and polymer-based packaging may not be possible, however, because each generation tends to suffer a loss of properties. Still, technology continues to improve the properties of these recycled materials. As it does with aluminum, glass, and steel, recycled content in fiber-based and polymer packaging reduces energy consumption and GHG emissions. High percentages of recycled content are possible, too. Packaging with 100% recycled fiber content is commonplace and often marked with a special logo (100% Recycled Paperboard Alliance). Percentages of recycled polymers tend to be lower. But food-grade containers made of 100% RPET, a percentage once thought to be impossible, are on the market.
Food-grade PET film with recycled content is available for use in thermoformed trays, clamshells, surface-sealed blisters, and other containers. Some films not only offer guaranteed levels of recycled content but also are produced with renewable energy ("SmartCycle" films, Klöckner Pentaplast).
Hurdles to sustainable packaging
Recycling rates for most packaging materials are low in the US, compared with many other parts of the world. Rates range from about 20% for glass containers to 78% for corrugated boxes (see Table I). To raise recycling rates, collection rates must increase. Increasing collection rates would entail convincing business, government leaders, and consumers to view used packaging as a raw material rather than waste, improving the reach and efficiency of the collection infrastructure, and advancing sorting technology to increase the purity of sorted material streams. It's also necessary to address economic factors to ensure that collection programs generate income, or at least break even, rather than drain community resources. A particularly important goal should be to change consumer behavior to eliminate the reasons for not recycling such as laziness, inability or unwillingness to pay fees for curbside collection of recyclables, absence of curbside collection or convenient drop-off programs, and lack of collection points.
Hallie Forcinio is Pharmaceutical Technology's Packaging Forum editor, 4708 Morningside Drive, Cleveland, OH 44109, tel. 216.351.5824, fax 216.351.5684, firstname.lastname@example.org.