Environmental Engineering Reference
In-Depth Information
Currently, most packaging materials are used alone and more frequently as a combination
of two or more materials. For instance, food packaging made of paper contains either a plastic
or an aluminum liner to protect the food from oxygen and light or to prevent leakages. On the
downside, multilayer packaging interferes with recyclability.
As stated before, with the exception of PLA, at the present time, there are no packaging
materials for food products that can perform cradle-to-cradle cycles. There is a need to find
resins that can be recycled an infinite number of times, composted so the nutrients can get
back to the soil, and renewable energy to make them. In the meantime, the best plan to
reduce the environmental impact of packaging is to go back to the 3Rs: reduce, reuse, and
recycle.
Reduce includes reduction of materials and energy in the production of packaging; reuse
involves the use of returnable containers whenever possible; and recycle incorporates recycled
materials when possible from the technical and food safety points of view.
Relative mitigation of packaging environmental impact
As with any other product, packaging produces several impacts that many times are not strictly
correlated. So, as one impact is minimized, another one may increase and vice versa. A typical
example is the debate of whether paper or plastic grocery bags are better for the environment.
Whereas paper is made from a renewable resource, it does not mean that the impact is lower
than plastic. Paper production from trees produces deforestation of native species, so high-
yield species can be planted instead; consumes huge amounts of water and energy; and pro-
duces air and liquid effluents. In addition, all the operations from cutting trees to produce
chemicals for the pulping process to transportation and processing is based mainly on fossil
fuels. Plastic bags, on the other hand, are produced from nonrenewable resources, but they
take about a third of the energy to produce and transport than their paper counterpart of the
same size (Boustead Consulting and Associates, 2007; Pimentel et al., 2009). But if not prop-
erly recycled, plastic bags became a significant waste stream for landfills.
Another specific example of impact reduction for packaging is beer bottles. Table 12.4
shows the environmental impact of beer packed in four different types of bottles (i.e., PET,
glass, aluminum, and steel) for a specific brewery in Belgium. Certainly, the results apply for
this specific brewery, but they are indicative of the relative impact of different packaging
options (Brody, 2009). Across all categories, glass is the worst option as packaging material,
and steel cans are the best. In terms of energy consumption, aluminum is marginally better
than PET, but it has higher global warming potential and a slightly higher effect on acidifica-
tion. The impact of aluminum bottles can be improved significantly by using recycled alu-
minum instead of virgin. As mentioned before, recycled aluminum needs less energy for its
Table 12.4
Environmental impacts of different choices of beer packaging using 100 liters of beer as
function unit for Martens Brewery in Belgium.
Primary
energy
(MJ)
100-year global
warming potential
(g equiv/CO
2
)
Acidification
(g equiv SO
2
)
Eutrophication
(g equiv PO
4
)
Water use (L)
Steel can
723
52,770
216
117
824
Aluminum can
911
65,762
293
118
866
PET bottle
986
58,243
234
120
877
Glass bottle
1,178
91,981
362
126
1,394
Reproduced from “Beer Packaging Study Challenges Preconceptions” Life Cycle Analysis Study, by Sidel, 2008.
