With packaging contributing 50% to municipal solid waste by volume, determining the amount of energy and environmental impacts for packaging is important. Tellus Institute assessed plastic, paper, glass, aluminum, and steel¹. Each packaging type was measured by environmental impact of production and the environmental impact of disposal.

To measure the impact of each packaging material, Tellus used a monetary scale. Environmental impact costs were represented by the price society is willing to spend to prevent pollutants from entering the environment. These prices are not the actual price to sustain our environment, but they are useful for comparison.

For each material, Tellus included all direct energy use and controlled emissions. They also included all indirect energy and controlled emissions within a one step range. As an example, the electricity used in production was included, as was the coal to produce the electricity. However, the resources used to mine and process coal were excluded as they are outside of the one step range.

SPI #2 Plastic Name $/Ton Common Uses High-density polyethylene Milk jugs, liquid detergent bottles, grocery bags Linear low-density polyethylene Plastic films (bread bags, produce bags, shrink wrap) Polypropylene Plastic lids, packaging, automotive, appliances, carpeting Polystyrene Styrofoam, cold food containers, insulation, disposable plates, cutlery, automotive parts, toys, housewares, appliance parts, wall tiles, radio, TV housings, furniture, luggage Polyethylene terephthalate Soda bottles Polyvinyl chloride Construction piping, plastic bottles, upholstery, flooring, wall coverings, sidings

Table 1 - $/ ton is the environmental impact cost of manufacturing each plastic. HDPE, LDPE, PP, and PS have roughly the same environmental impact rating. PETE is about twice as high as these four. PVC is nearly six times higher than PETE primarily because of carcinogenic emissions. The environmental cost of disposal is $4 per ton excluding PETE, which is $5 per ton. Recycling was excluded from analyzing plastic because only 1.8% of packaging plastic is recycled.

Recycling some plastics might be worse than throwing them out. Though there is no decisive research on the environmental impacts of recycling plastic, relating the economic cost of disposal to recycling shows that the cost to recycle plastic is $360 per ton while normal disposal cost is $250 per ton. The difference is mostly caused by recycling collection trucks. Unlike garbage trucks, recycling collection trucks don't compact their load. Because light plastics fill up a lot of space, recycling collection trucks end up consuming a lot of fuel for small quantities of plastic, increasing the environmental impact.

For paperboard packaging, five different kinds were assessed. Each has the same environmental disposal cost, $2 per ton. The environmental cost of production of bleached paperboard, as shown in Figure 1, is highest at $330 per ton while corrugating medium is the lowest at $80 per ton. The other three are similar, about $270 per ton.

Figure 1 - The environmental cost of five paperboard products. Bleached paper board is used in milk cartons and ice cream containers. Unbleached coated boxboard is used in cereal boxes. Linerboard is flat cardboard. Corrugating medium is the material between two pieces of linerboard. Finally, an example of unbleached paper is wrapping paper.

Recycling does decrease the environmental cost for unbleached coated boxboard and linerboard in half, to $135 per ton. The cost of corrugating medium increases through recycling to $183 per ton.

Though recycling paperboard products decreases the environmental cost of manufacture, waterborne emissions increase. Recycling paper products causes the wood fibers to break. As the fibers break and become smaller, they become harder to catch and escape into the water stream. Harmful metals in ink also escape through the pulping process. Although waterborne waste increases, recycling does reduce the overall environmental cost.

Glass has the smallest environmental cost per unit weight, $85 per ton for virgin materials and $55 per ton for recycled. Though glass has the lowest environmental cost per ton, glass requires greater quantities to be an effective packaging material. If more material is used, then the environmental cost is higher. To demonstrate this, ILEA used data for half gallon juice containers provided by Tellus. A glass juice container has an environmental impact of 0.19 cents per unit. Recycled glass is at 0.15 cents. Paperboard carton runs at 0.06 cents per unit. Though glass has the lowest environmental impact by ton, in real world applications it has a higher environmental impact.

Figure 2 - Environmental impact of three half gallon juice containers. Though glass has the lowest environmental impact per ton, when compared on a weight relative model, glass is much higher. This data is relevant for milk containers as well.

Virgin aluminum has an environmental cost of $1,900 per ton. Recycling is very effective for aluminum, eliminating 96% of the energy used to produce a ton of new sheet stock. The environmental cost of recycled aluminum is $310 per ton. The substantial decrease is due to eliminating the mining and smelting process. The environmental cost of disposal is $5 per ton for both recycled and virgin feedstock.

Steel is coated with tin and used to make cans. Its environmental cost is $230 per ton. Recycling has little effect on the environmental impact of steel manufacture. Though mining is eliminated, remanufacturing steel requires substantial amounts of energy. The difference reduces the environmental cost by only $10 per ton. For steel the environmental cost of disposal is $2 per ton.

A number of conclusions can be drawn from this study. First considering that the environmental cost of production contributes 99% of the environmental harm, reducing disposal isn't going to help as much as cutting production. The problem of packaging facing the environment is not a problem related to disposal. It is a problem of production, which directly relates to consumption. The solution according to the Tellus scale isn't a matter of improving recycling or disposal rates, but consuming less.

When it comes to deciding which product to consume, PETE (1), PVC (3), and virgin aluminum should be avoided. Each has a very high environmental cost. Second, though glass appears to be an excellent packaging material (when compared on a cost per ton basis) because glass requires higher volumes for effective packaging, it actually has a higher environmental impact per use than paper and plastic. Hence glass should be avoided when possible. Third, recycling aluminum is exceptionally beneficial. Recycled aluminum, plastic, and paper have relatively similar environmental costs on a per ton basis. Between these three, the product with the least packaging is preferred.

¹ Tellus Institute. Tellus Packaging Study. Boston: Tellus Institute of Resource and Environmental Strategies, 1992.

² SPI is the Society of the Plastics Industry. SPI numbers are found printed on most plastic containers inside the familiar, three-arrow recycle symbol.