Source Reduction

One powerful way to reduce the environmental impact of a package (or product) is to use less material in its manufacture. That translates immediately into less use of raw materials and less waste at the end of the package life. Usually it also means less use of energy throughout the package life cycle. Since it also almost always translates into lower cost (since less material must be purchased), downgauging of packaging (making the package thinner) has a long history in packaging. In the past, the driving force for this type of source reduction was cost reduction. More recently, environmental benefits have assumed a significant, though usually secondary, role.

A variety of examples can be given of this type of source reduction. Plastic soft drink bottles, for example, are lighter than they used to be. In 1977, when 2-liter PET soft drink bottles were introduced, they weighed 68 g (including the HDPE base cup). In 1999, the redesigned bottles weighed only 49 g, a 27% reduction. With about 5.6 billion of these bottles being sold each year, the total savings are approximately 200 million pounds per year [11].

Procter & Gamble Corp. (P&G) and its bottle supplier, Continental PET Technologies, redesigned the PET bottles P&G used for vegetable oil. The new design used 30% less plastic than the old design, while achieving the same strength, and resulted in reduction of about 2.5 million pounds of plastic per year. In addition, the rectangular design for the new bottle enabled the bottles to fit in the shipper more compactly than the old cylindrical bottles, resulting in the elimination of about 13 million pounds of corrugated board per year [12].

The replacement of LDPE films by thinner LLDPE films for a wide variety of packaging applications has already been mentioned. Metallocene polymers can provide similar benefits.

When source reduction results in less of the same material used, and no other substantive changes, the environmental benefits are clear. Often, however, substantial source reduction is accomplished by changing materials, package style, and a variety of other features. With such changes, a life-cycle analysis approach is the only truly accurate way to evaluate the overall environmental effects of the change. However, such analysis are complex and costly, and there remains no universally accepted way to combine disparate environmental impacts into a usable score or set of scores for evaluating environmental costs and benefits of the two (or more) alternative packaging systems. Nonetheless, a number of studies suggest that, by and large, if substantially less material is used, the overall environmental effect is likely to be positive.

Substantial amounts of source reduction can often be gained by switching from glass or metal to plastics packaging and by switching from rigid or semirigid packaging to flexible packaging (usually containing plastic). While such reduction is usually measured in terms of weight, there is typically a reduction in the volume of packaging material used as well.

When Clorox switched from glass bottles to plastic bottles for barbeque sauce and salad dressing, the new PET bottles weighed 85% less than the old glass bottles. The result was reduction of nearly 30 million pounds of glass per year. Use of corrugated boxes was cut by 2 million pounds per year since the plastic bottles used less space [12]. For example, 18-oz glass jars for peanut butter weigh 10.2 oz each. PET jars of the same capacity weigh only 1.7 oz, an 83% reduction.

Additional savings accrue during distribution, due to the weight difference. It takes three trucks to haul as much peanut butter in glass jars as two trucks can haul in plastic jars [11].

Many medical products have moved from rigid to flexible packages. Kendall Health Care switched from a thermoformed tray to a flexible pouch for a urine collection assembly used in hospitals and achieved a waste volume reduction of about 50%. Medchem changed hemostat packaging from a glass jar inside a foil-lined container to a plastic tray in a pouch and achieved an 80% reduction in packaging by weight [13].

A very rapidly growing type of packaging is stand-up pouches, flexible pouches that are designed to stand erect on the shelf and replace bottles, cans, or cartons. In 1995, Procter & Gamble won the Flexible Packaging Association's Green Glove Award for its stand-up bags for detergent, which used 80% less packaging than the paperboard box they replaced, as well as incorporating 25% postconsumer material [14].

In addition to reduction in package volume or weight, such packages can offer advantages that are less obvious. For example, the aluminum foil/plastic stand-up pouch for Whiskas cat food, which replaced a 10-oz steel can, is reported to require 30% less retorting time than steel cans because the pouch can be heated more quickly and evenly [15]. That translates directly into reduced energy use for the retorting process and probably into a decrease in the amount of cooling water required as well. Kapak Corp., a Minneapolis-based flexible packaging manufacturer, points to flexible packaging advantages in freight savings (one truckload of 1-liter pouches have the same holding capacity as 25 truckloads of rigid packages) and warehouse space (96% savings), as well as energy reduction (75% less manufacturing energy), and a 25:1 ratio for source reduction [16].

Of course, not all packaging reduction innovations meet with consumer success, and what is successful in one country may not be so in another. DuPont Canada estimated in 1990 that switching from HDPE gallon bottles for milk to twin-pack 2-quart LLDPE pouches could reduce the weight of discarded packaging by 58%. They further calculated that replacement of the mix of then-current milk packaging by pouches could reduce the landfill volume of discarded milk packaging by nearly 93% [17]. While such pouches have enjoyed some success in Ontario (where there is a deposit on HDPE milk bottles but not on pouches), they have not met much success in the United States.

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