Purpose and Background

Purpose and Background

Purpose

Environmentally preferable purchasing (EPP) is an activity of increasing importance for organizations large and small, in the U.S. and abroad. There is dramatic growth in the number of products that are touted as being environmentally preferable, and in the volume of information being provided about such products.

Given the environmental goals of your organization and the nature of its operations, which environmental impacts should you select as your top priorities for reducing through EPP? The Purchasing Impact Estimator (PIE) helps you by giving an objective assessment of the degree to which your organization's purchases are having an environmental impact.

PIE is designed to enable you to get your bearings and set priorities for EPP. You enter data on your annual purchasing, using your own purchasing categories. The tool enables you to match your purchasing categories to those in its database for which life cycle assessment (LCA) data are available. It then enables you to calculate and graphically visualize how much impact is associated with each of your purchasing categories, for a given category of environmental impact.

Thus, PIE enables you to:

  1. Enter data on your specific annual purchases, and on this basis to:
  2. Prioritize environmental impact categories; and on this basis to:
  3. Prioritize purchasing categories for EPP action.

There is one more thing that PIE is designed to help you do. That is to estimate and report progress and benefits from your ongoing EPP efforts. You can enter and compare purchasing data for different scenarios, and for different years, in terms of the environmental impacts the purchases entail. Use this feature to compare alternative purchasing strategies. As you reduce your use of high-polluting inputs to your operations, you can then calculate the resulting environmental benefits and report them to stakeholders.

Background

History
This tool was originally created as a desktop application for the Texas Commission on Environmental Quality (TCEQ), and has since moved online to this location.
Credits
The participants in this project are listed on the credits page.

Technical Information

Life Cycle Assessment (LCA)

LCA is an environmental management tool that is codified by ISO 14040. "LCA addresses the environmental aspects and potential environmental impacts 2) (e.g. use of resources and the environmental consequences of releases) throughout a product's life cycle from raw material acquisition through production, use, end-of-life treatment, recycling and final disposal (i.e. cradle-to-grave)." (ISO 14040). For more information, a good starting place is the UN Life Cycle Initiative Site or, of course, Wikipedia.

Data Sources

There are many available data sources for Life Cycle Assessment Information, and they are experiencing rapid improvement. The PIE project uses a combination of datasources, including the US Input/Output database by Sangwon Suh, PhD (see credits for more information), and the EcoIndicator99 Impact Method by Marc Goedkoop and Renilde Spriensma of Pre Consultants.

Calculations

The basic calculations for PIE were done in the original EPPA tool (in Analytica). That tool is available for download here. The model requires Analytica player to view it. A trial version, which becomes Analytica Player after 15 days, is available from Lumina. The EPPA is a traditional LCA model, where the technosphere flows are combined with elementary flows to reach an inventory. Then an impact method is applied, which is EcoIndicator99(H).

PIE provides the user with "Impact Factors" per dollar (derived in the EPPA tool). The user enters the amount he or she is spending on a product category, and this number is multiplied by the impact factor to reach the total product impact.

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