Log Assignment
LCA Assignment

to determine environmental friendliness


What is a "green product?"


The entire life cycle of any device may be thought broadly to consist of the following general stages: (1) raw material extraction, (2) refining of material (3) manufacture (4) distribution (5) use (6) disposal (7) waste management. There are several transportation links between and during these stages.

  1. Draw the life cycle of an Aluminum can as described in Natural Capitalism, Chapter 3. Show the geographic locations and approximate distances of transportation on the figure. What are the routine emissions from this life cycle?

  2. What might be ways to reduce the environmental impacts of this life cycle?


Do this assignment in groups of 5 or 6. You must work in interdisciplinary groups.

The concept of "environmentally friendly" products or "green products" has gained a lot of attention in the past 10 years or so. As a way of determining which of two equivalent products causes less pollution and environmental impact, an analysis called the Product Life Cycle Analysis (PLCA, or LCA for short) has been used.

In this project you will conduct a PLCA on two products that are alternatives for the same use (e.g., paper napkins and cloth napkins). Several resources are listed at the end of this assignment to guide and aid your work

  1. Select a pair of alternatives for a consumer product with a life of 0 to 10 years. Possibilities include:

    - Glass bottles and plastic bottles for soft drinks
    - Cloth diapers and plastic diapers
    - Incandescent and fluorescent light bulbs
    - Disposable and rechargeable batteries
    - Liquid and powder detergents
    - Alternate Packaging materials
    - Automobiles

  2. Draw a flowchart showing the material, energy, and residual flows.

  3. Do PLCA for the 2 products. This is to give you experience in estimating:

    (1) the resources - materials and energy - embodied in products we use daily;
    (2) the waste flows and emissions to the environment during manufacture, use, and ultimate disposal of the product.

    Use concept maps, tables, etc., to show the environmental burdens/ impacts, and other factors consumers usually consider when buying a product.

  4. Based on the experience of your analysis and personal experience, develop a set of criteria for deciding on the "better product choice" from the point of view of resource conservation and environmental quality. What other factors would you consider besides these two?

    - Propose the weight each of these criteria should have.
    - Outline the set of values that you considered in this part.
    - How might the criteria (or, the weights) change with the culture of the society?
    - What may be the problems in implementing the factors determined by these criteria into the design of products?

  5. Determine which is more environmentally friendly. Explain your reason as you would explain to a member of the public who does not have your expertise in environmental impacts.

  6. Look at any two products you have around for any environmental label. Briefly describe what you learn from the labels. Design a logo and short slogan for the green product that you worked on.

  7. Write and present a report on the project. The project report should show the detailed calculation of the LCA including your assumptions, and approximations, the factors you considered in your assessment, the difficulties and uncertainties in the analysis.

    A detailed discussion at the end should include the problems with doing the LCA, and to what extent it helps consumers make informed choices.

  8. Formal oral presentation: Present your results in a formal presentation in class. Each group presentation should be no more than 5 minutes. The presentation should be a clear summary of your work, including the uncertainties, assumptions, etc. The discussion on page 25 -26 of the SETAC Chapter 2 should provide a good guideline in preparing the presentation.


  1. From: SETAC, A Technical Framework for Life-Cycle Assessment, SETAC Foundation, Washington, DC, 1991 -.

    - Chapter 2: Framework for a Life-cycle Inventory
    - Chapter 3: Raw Materials and Energy

  2. Paul R. Portney, "The Price is Right: Making Use of Life Cycle Analysis," Issues in Science and Technology, Winter 1993-94, pp. 69-75.

  3. Karen Shapiro, Life-cycle Evaluation of Packaging Materials, Proceedings of IEEE Conference on Electronics and Environment, 1993, pp. 106-110.

  4. Martin Hocking, "Paper versus Polystyrene," Science, Vol. 251, February 1, 1991.

  5. "Environmentally-sound product development based on life-cycle assessments (LCA) - 'from cradle to grave'," in Sven-Olof Ryding (ed.) Environmental Management Handbook, Lewis Publishers, Boca Raton, Florida, 1992., pp. 435-438

  6. Amy Lynn Salzhauser, "Obstacles and Opportunities for a Consumer Ecolabel", Environment, Volume 33, no. 9, November 1991, pp.10-

  7. U.S. Congress Office of Technology Assessment, Executive Summary, Green Products by Design, U.S. Government Printing Office, Washington, D.C., 1992.

  8. Flowchart form : Ayres R.U. and A.V. Kneese, "Pollution and Environmental Quality" in Perloff, H. (Ed.) Quality of the Urban Environment, Resources for the Future, Washington, D.C,., p.37

  9. LINKS?
  ©Copyright 2003 Carnegie Mellon University
This material is based upon work supported by the National Science Foundation under Grant Number 9653194. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation.