LCA handout2 by rsnRgbG5


									                            Life Cycle Assessment (LCA)
                                 Class Notes, Activity
                                     Adam Kiefer

General Overview: A life cycle assessment (Life Cycle Analysis, LCA) is an evaluation
of a consumer product’s environmental impact over the entire life of the product.
This means that we are not concerned about the waste generated by one application
of a product, rather we are concerned with the production, use, and fate of a

Part I: Powerpoint Presentation / Intro to the LCA
NOTE: You are free to use the .ppt slides provided with this case study. The instructor
may be better off coming up with their own presentation using some or all of the slides
provided. Using the powerpoint presentation associated with this activity, students
will be introduced to the general concepts of a qualitative pictorial life cycle analysis
of a variety of items, including an automobile and EtOH based biofuels. The key
thing to remember is that LCAs are very detailed, and often contain a lot of math.
Students should walk away from this exercise with a purely qualitative
understanding of the LCA. Similarly, students should recognize the complexities of
manufacturing, use and disposal.

Part II: The Toothbrush, Construction of the LCA.
Goal: To reinforce the students understanding of how even a simple item plays a
complex role in consuming non-renewable resources.

Lesson Plan: Pass around a few identical toothbrushes in its original packaging,
including the price. While students are laughing at you because you have assumed
they have never seen a toothbrush before, you should encourage them to notice the
fine details of the toothbrush that they perhaps had not noticed before. Also, on the
board, write up the three major stages of the life cycle: Manufacture, Use, and
Disposal. Write each of these 3-5 ft. apart on the board in an oval. If you don’t leave
enough space early on, this project will become illegible:
After everyone has seen the toothbrush, tell students that the class has been hired to
do a qualitative life cycle analysis to determine the environmental impact of the
toothbrush on American society. Start off with the easiest component of the LCA,
use. Ask students what input does the average person use to operate a toothbrush.
(Water, toothpaste, etc.). What are the byproducts of the usage of a toothbrush? You
can make this answer as simple or complex as you want. I always include
wastewater. I will include biological waste (saliva, bacteria, virus) as well as
chemical waste (fluoride, artificial coloring). Creating a flow chart allows students
to see the process as it “occurs”. Also Show the direct connection (fossil fuels)
between Manufacture, Use and Disposal/Recycling/Reuse. At this point, your flow
chart should look something like this:

Explain to students that an LCA is a living thing, and we will be able to come back to
the “use” category later. Now concentrate on Disposal/Recycling/Reuse. Disposal is
relatively easy. We take the toothbrush and throw it in the trash. Students often
realize that the toothbrush goes to a dump and takes up space for a very long time. A
few exceptional students may recognize that eventually the toothbrush will
decompose to CO2 ( a greenhouse gas) after hundreds of years, but I wouldn’t count
on it. There is a difference between reuse and recycling. Recycling is where the
product has a series of operations performed on it, so that it can be reused either for
its original intention ( a toothbrush) or a new process (a soda/pop bottle). In this
case suggest to the student that you could bleach or boil the toothbrush to sterilize
it, thus recycling it for use as a toothbrush. Recycling regenerates the “cycle” by
directly reconnecting “Disposal/Recycling/Reuse” with “Use”. Reusing (in this case)
indicates that the object is used as is for an alternative purpose. A toothbrush can be
used as a cleaning utensil. Your diagram should look like this:
Aside: Students often have trouble distinguishing between reusing and recycling.
Stress that reusing is often the result of no external influence and it implies that the
product remains relatively unchanged. For example, a tire that has a hole in it can be
reused as a tire swing, or cut into strips and made into the soles of shoes. This is
considered reusing. Recycling often has some external influence on it, such as
sterilization, or melting. Carpet can be recycled by chemically breaking it down into
its starting materials, and then remaking the carpet from these materials. More and
more often these terms are being used interchangeably.

And now on to the most difficult component of the LCA, manufacture. Begin by
asking the students to describe what components make up the toothbrush. A
student will often volunteer the word plastic. In this case, ask the students how
many types of plastic comprise the toothbrush. Typically, the bristles are different
than the rubbery handle, the hard composite stem, and the clear packaging plastic.

Ask the students if they believe that these plastics are produced where the
toothbrushes are made. If not, where do the starting materials come from
(petroleum). At this point students should realize that the manufacturing
component is quite extensive. Questions the instructor can ask to spur conversation:
   1) Do you think plastic is naturally white, blue or red, or are dyes required.
   2) 2) Lets look at the packaging which we discard prior to using the toothbrush.
       What is it made from (paper, ink, dyes adhesives)
   3) How do these components get from the factory to the toothbrush factory
LCA should look something like this:
What happens if the price of crude oil increases? Remember, this is a crude outline…
your students may come up with things that I’ve not even thought of.

Student Activity:

Break students into groups of ~4 students. Give each group $3.00 (either real or
imaginary) and tell them to purchase an item from the student union / bookstore.
The item may not have moving parts or be mechanical… keep it as simple as
possible. A quick word of advice/warning: students love to purchase food. Food
LCAs can be quite extensive, but offer students a chance to figure out where each
ingredient comes from (the field or the factory). I like allowing the students to
purchase their own item, but logistically it might be easiest to bring in a number of
inexpensive items. In class give the students ~ 5 minutes to sketch out an LCA for
the item. This should give you enough time to determine if they are on the correct

On a piece of posterboard or a .ppt presentation, have students present to the class a
2-4 minute presentation laying out an LCA for their product. Make sure it is
abundantly clear that each student in the group must present some aspect of the
LCA, and students must discuss why they purchased the item.

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