SOCIETAL BENEFITS OF PLASTICS - Plastics and Environmental Sustainability - page 187

5.2 BENEFITS FROM PLASTIC PACKAGING
Packaging of products is a prerequisite for their sale in today's market
and serves several important functions. Safe containment of the item
(Buonocore et al., 2014), especially food, pharmaceuticals, or cosmetics, is
the primary benefit of packaging. Plastics serve this function particularly
well, and conversion of other types of packaging into plastic packaging is a
common trend. The primary advantages of plastics in this application are
lightweight, relatively low environmental footprint, bioinertness, and low
cost. The functionality afforded by general-purpose packaging 5 includes the
following:
1. Containment against damage, loss, and waste by spillage. Convenience
in ease of handling and portioning in food packaging
2. Protection of contents against microbial contamination
3. Protection of contents against spoilage due to oxidation, hydrolysis, and
intrusion by chemical species. Preservation of freshness of the packaged
food items
4. Screening out of ultraviolet or infrared (IR) radiation that may degrade
with the packaged item
5. Communication of information about the contents and their use to the
consumer
Sustainable use of material resources requires the most economical and
energy-efficient material be selected for packaging. A simple metric of
environmental merit in packaging might be the embodied energy (EE) and
the global warming potential (GWP) associated with the manufacture of the
package, per unit volume of contents. While the environmental footprint
of a package cannot be adequately specified merely in terms of its EE and
GWP, even a comparison based on just these two estimates can be useful.
A wide range of environmental impacts (as discussed in Chapter 2 ) need
to be taken into account to define the footprint comprehensively. However,
the data for glass, plastic (poly(ethylene terephthalate) (PET) and HDPE),
and metal cans (aluminum and steel) as packages for beverage (1 l) are
shown in Table 5.3 . Aluminum is the worst performer using either criterion.
The steel can 6 is the most energy efficient but is not the best in terms of
GWP. Plastic packaging is less energy intensive than glass or aluminum and
matches the GWP of the glass bottle. Assuming the functionality provided