Environmental Activities for the Classroom:
Product Life-Cycle Analysis
Objective: To have students become aware that the
toxic heavy metal sludge to 1 gallon of water use or
products they buy have an impact on the environ-
consumption of 1 btu of energy? In addition, there are
ment beyond that of disposal of the packaging or
economic, employment and social issues tied into this
other wastes generated from use.
Grade Level: 7-12
For example, this analytical technique has been
adopted by some manufacturers who hire private
Class Time Estimate: 2 or more hours
research firms to conduct LCAs for their products. This
has raised great concern in scientific and environmen-
Materials needed: shoes, paper, pencil
tal circles. With a growing environmental conscious-
ness on the part of consumers, marketing a product as
“environmentally-friendly” can mean money in the
bank for manufacturers. As an example, three LCAs
have been conducted on cloth vs. disposable diapers by
separate firms hired by different groups. Each analysis
Dissecting a consumer product into all the various
came out with different results and each group mar-
processes that contribute to its production and disposal
keted their products using the numbers from the studies
can help us better understand how our consumer habits
affect the environment. Consumption of products
drives an array of extraction, manufacturing, process-
To help alleviate concerns over the trend to use LCA as
ing, transportation and disposal operations. An analysis
a marketing tool, the Society of Environmental Toxi-
of these operations, called life-cycle or cradle-to-grave
cology and Chemistry (SETAC) has established
analysis, documents the inputs (water, energy, raw
guidelines for conducting LCAs by both governmental
materials) and outputs (products and wastes), for these
and private agencies, as well as developed a code of
ethics. This group suggests that an LCA should include
three basic parts as described below: inventory,
Life-cycle analysis (LCA) has most often been used to
impact, and improvement.
compare two or more products, such as plastic vs. glass
vs. aluminum beverage containers, for their environ-
mental impact. This type of analysis can point out
strengths and weaknesses in the production and dis-
This includes making decisions on the depth of the
study. In diapers, for example, you would want to
include: manufacturing, packaging, distribution, use,
While LCA can be used as comparative tool, compar-
and disposal. One step more detail would include
ing energy usage between plastic, glass and aluminum
extraction or production of the raw materials to pro-
beverage containers, for example, it does not provide a
duce the separate ingredients of plastic, paper, cotton,
way to rank the importance of the factors examined.
etc. Conceivably, you could spin off into even further
For example, what should be ranked higher in impor-
subdivision such as cotton production and chemicals,
tance in maintaining a healthy environment: energy
energy, and equipment required for this. Thus, a need
usage, air quality, water quality, solid waste? How do
exists to determine the boundaries of the LCA.
we compare the environmental impact of 1 pound of
Within these boundaries, you need to decide what you
plexity of life-cycle analysis, the concept of this
will and will not gather data on in your environmental
activity is to introduce students to thinking beyond the
assessments. For example, do you include erosion, loss
final product bought at the store and disposed of later
of habitat and biodiversity, groundwater contamina-
on. It is to encourage their understanding of the many
tion, generation of global warming gases, etc.?
processes that can be involved in manufacturing a
product and the effects of these processes on the
With your list of what you will include, and what you
environment. This activity can be expanded as much as
won’t, a mass balance determination is performed.
Basically, a mass balance equation is: Inputs = Out-
puts. Inputs include both renewable and nonrenewable
1. Introduce the concept that all production processes
raw materials, energy, water, etc. Outputs include
generate some type of waste. Ask everyone to wear a
product, any by-products, air, water, and ground
pair of tennis shoes to class the following day. Provide
pollution, and solid waste. This mass balance is done
a couple of old tennis shoes for those students who
for every stage of the product life-cycle from extrac-
may not have them, or forget to wear them.
tion of raw materials to disposal/recycling.
2. Have each student take off a shoe and put it on the
desk in front of them. The student should make an
attempt to draw their shoe. Have them examine it
This portion of a LCA is to determine the relative
closely and list all the different types of materials (to
destructiveness of the pollutants. Here the question of
their best guess) that the shoe is made of a label these
making decisions on ranking occurs. For example, is a
parts on their drawing. You may want to do the same
pound of benzene in the air, a pound of herbicide in the
process on the chalkboard for a tennis shoe of your
water, or loss of habitat for a threatened species the
own to aid in later discussion. This list will probably
most important? As of now, no agreed upon method to
include such items as leather, nylon, canvas, plastic,
do this type of ranking has been determined.
rubber, cotton, etc.
3. Add to the list the packaging materials the show
came in from the store (this could include cardboard
By having all the data pieces gathered in the inventory
shoe boxes, tissue paper, plastic bags, paper bags, etc.).
and impact steps before them, analysts will have
improved opportunities to find methods to prevent or
4. Start a discussion by asking the students where their
reduce pollution from occurring. Without this analysis,
shoe came from. While the obvious answer will be ‘the
reductions in one aspect may result in increased
store,’ expand their understanding to include the
pollution in other aspects of production.
various components they just listed. For example, the
leather came from a factory that processes and cuts
leather which is then delivered to the shoe manufac-
turer. Further back to the raw materials, the leather
comes from cattle via a slaughterhouse and tanning
This is an activity using hypothetical leather tennis
factory. You may want to develop a type of flow chart
shoes as the product under study. Students will work
similar to that in Fig. 1 for several of the components
through a simple life-cycle analysis of a tennis shoe
of the shoe to get across the idea that all the various
and discuss the issues involved. Because of the com-
parts are a result of a number of manufacturing pro-
Leather drying &
Figure 1: Simple Flow Chart for Leather Shoe Parts
5. Examine one of the manufacturing processes in
A (leather) or B (synthetic) is better for the environ-
depth and develop a chart such as the one illustrated in
ment (there is no correct answer). Is it possible to
Fig. 2 which uses leather production as an example.
weight one aspect (air, water, land pollution or solid
Introduce the concept that his process requires energy,
waste) as being more important than another? How?
water, and raw materials and produces a product
Why? Who makes these decisions in our society?
(which goes on to the next step for further manufactur-
ing) and air, water, or land pollution as well as solid
8. Have students discuss ideas on how to decrease the
waste. Discuss that for each part that goes into the final
impact of consumerism on the environment.
product, a similar chart could be developed.
6. Discuss the impact this process has on the environ-
ment, the fact that all of the shoe parts have some
Have students do research on what “environmentally
impact on the environment, and that everything we buy
friendly” means in terms of marketing of products in
as consumers comes with an environmental price tag.
the U.S. Extend this to other countries that have
labelling procedures to alert the consumer to the
7. Introduce the term life-cycle analysis/cradle-to-
product’s environmental qualities (Germany - Blue
grave analysis. Explain to the students that they have
Angel; Canada - Environmental Choice; Japan -
just done a simplified version of a life-cycle analysis.
Ecomark; Australia - Green Spot).
Draw Table 1 on the board. Discuss which tennis shoe,
All other shoe parts
from other processes
Leather drying &
Outputs (Wastes + Products)
Figure 2: Inputs and Waste Outputs from leather components of a tennis shoe.
& Solid Waste
2 gal. 4 lbs.
2 lbs. haz. sludge
4 gal. 1 lb.
8 lbs. inert
1 lb haz. sludge
3 lbs. non-haz.
Table 1: Hypothetical example of life-cycle environmental impacts of shoes A (leather) and B (synthetic) per
100 pairs of shoes produced.