Environmental Engineering Reference
In-Depth Information
ENVIRONMENTAL IMPACTS OF FOOD PACKAGING
The positives
The main positive attribute of food packaging is the adequate preservation of the food product
from the time it is produced to the time it is consumed. Packaging with inadequate functional-
ity leads to earlier food spoilage and the generation of food waste, which can be the result of
microbial contamination, unwanted chemical reactions, or mechanical breakage. In addition,
food packaging has the following benefits:
Controlled atmosphere packaging and smart packaging contribute to the extension of the
shelf life of foods beyond what it would be in a regular package.
●
Sterilized shelf stable products can be viable for long periods of time thanks to tight pack-
aging that prevents recontamination.
●
Packaging facilitates transportation and avoids waste due to breakage and contamination.
●
Food products packed in food-processing plants reduce waste and are more efficient in
giving use to trims and off-grade products that otherwise would go to waste at the retailer
or consumer's kitchen.
●
Resealable packaging helps to maintain the food fresh for a reasonable period of time once
the product is initially opened thus preventing waste.
●
The negatives
From the consumer's perspective, one of the most visible negative aspects of packaging is the
production of solid waste. However, food packaging has another hidden aspect to the untrained
eye, which is: the amount of resources and energy that are used in the construction of a short-
lived item, which unless reused or recycled, is disposed of only after a single use.
Packaging manufacturing uses mostly nonrenewable energy and nonrenewable resources
in the form of mineral ore, oil, and natural gas. Packaging made from renewable resources,
such as paper, is energy- and water-intensive and contributes to the destruction of ecosystems,
particularly in semitropical countries where native jungle has been cut and replaced with fast-
growing trees for paper production.
Consumption of nonrenewable feedstocks
Plastics are produced from crude oil and natural gas. It is estimated that in the United States,
4 percent of petroleum is consumed to make plastic packaging (Pimentel et al., 2009). Most
plastics used in food packaging are produced by polymerization of the monomers shown in
Table 12.1. These monomers are produced by chemical reactions that start with the “cracking”
of primary distilled fractions of crude oil (naphtha) followed by a series of chemical reactions
of variable complexity. For instance, a hydrogen atom of ethylene is substituted by chlorine to
form the monomer vinyl chloride; ethylene terephthalate is produced by combination of dime-
thyl terephthalate and ethylene glycol; dimethyl terephthalate is produced by the sterification
of terephtalic acid with methanol; and terephtalic acid is made from the oxidation of p-xylene
(Baker and Mead, 2000).
In places with abundant natural gas, the ethylene used for the production of polyethylene,
is separated from the gas current in specialized separation plants or converted into ethylene in
cracking plants and then rerouted to polymerization units where it is transformed into low-
and high-density polyethylene or used as a feedstock for the preparation of other monomers.
