Environmental Engineering Reference
In-Depth Information
services, thus creating the need for hard data. Also, the availability of data from the conduc-
tion of LCAs has corporate advantages, including:
1. Comparison of the environmental impact of different products or processes.
2. Transference of environmental impacts from one media to another (e.g., eliminating
air emissions by scrubbing a gas effluent, thus creating a wastewater effluent instead
[EPA, 2006]).
3. Understanding what steps of the entire process are responsible for the majority of the impacts.
4. Making improvements in the process and raw material acquisition (e.g., virgin raw
material versus recycled).
5.
Having data for the purpose of environmental declarations.
6.
Acting in response to customer demands.
7.
Showing environmental stewardship.
8.
Designing products more benign to the environment.
Problems associated with LCAs
As seen in the case of the canned green beans, conducting an LCA is a time-consuming
process that translates into a cost measure for a company. If the analysis is done by the com-
pany, or a consultant that has a stake in the product or service, then the results are tinted with
a shadow of doubt about the objectivity of the data used in the process. For that reason, more
transparent LCAs come from universities or independent nonprofit organizations with no eco-
nomical links with the company. However, this can also have some problems because compa-
nies contract scientists as service providers.
Another limitation of LCAs is that the results depend on where the analyses are conducted.
Different research groups in the same or different regions of the world will produce diverse
results depending on assumptions made, estimation of inputs and outputs, and methodology
used. Conveniently, variation in the methodology can be minimized by following standard
procedures such as the one described by the ISO 14040. Still, inconsistency in the conclusions
can surface as a result of different assumptions and simplifications of environmental impacts
made by different researchers.
Conducting an LCA using ISO standards
There are different ways to conduct an LCA, but the principles are basically the same: an
assessment of all the materials, energy, and wastes produced by each step in the production of
raw materials, manufacturing, distribution, and final disposal of a product. Figure 4.2 shows a
generic diagram of a product life cycle for a food product from production of the raw material
to disposal (cradle-to-grave analysis). Technically speaking, the disposal phase only includes
solid waste, such as packaging and food scraps, and does not take into consideration the dis-
posal of human waste (sewage treatment), which would create allocation difficulties. (The
allocation problem and different types of LCAs will be discussed in another section of this
chapter.)
Currently the mainstream guidelines to conduct LCAs for any product, including food
products, are the standards provided by the International Organization for Standardization
(ISO), which developed the ISO 14000 family that provides specifications for the creation of
environmental managements systems. The ISO 14000 family contains two norms, ISO
14040:2006 and 14044:2006, that prescribe the methodology to conduct LCAs for any prod-
uct, process, or service. These two norms cancel and replace ISO 14040:1997, ISO
14041:1998, ISO 14042:2000, and ISO 14043:2000 (ISO, 2006a). Additional norms that are
