For this LCA, the objectives of the study were to:

1. Comprehensively define the environmental impacts over the whole life cycle for each of the three systems,
2. Provide an accurate comparison of impacts among the systems, and
3. Assess the influence of several key variables or characteristics, such as intensity of use (duration per dry or towels per dry), recycled content, alternative electricity sources, etc.

The intended audiences for this study included architects and interior design professionals, facility owners and operators, purchasers of hand dryers, and interested others. The intent of the study is to provide these audiences with the information they need to make a valid comparison of the life cycle environmental impacts of the systems in question. The impacts described in the study are estimates of potential impacts rather than direct measurements of real impacts.

The Functional Unit of the study is to dry 260,000 pairs of hands over a 10-year life cycle, which applies to all three systems and serves as a common basis of comparison. A System Description is another key element of any LCA. The three systems were each manufactured in the USA, each was assumed to be distributed in the same way, their supply chain distances were assumed the same, with similar packaging material and recycled at the same rate, each had a motor, optical sensor for activation, and powered by batteries for the paper towel dispenser and electricity for the two hand dryers in question.

Finally, the System Boundaries and Characteristics is another key element of the Scoping stage of the LCA process. The life cycle assessment methodology addresses the environmental aspects and potential environmental impact (e.g., use of resources and release of pollutants) throughout a product's life cycle. In this case the life cycles of the three systems were divided into their five principle life cycle stages: (1) Material Production; (2) Transportation; (including to the production site, to the point of use, and to the end-of-life location); (3) Manufacturing; (4) Use; and (5) End of Life (landfilling, recycling, or incineration). All identifiable 'upstream' inputs are considered to provide as comprehensive a view as practical of the total influence of each products system. As an example, not only the truck fuel to transport the system to the facility, but the energy to process the fuel are factored in to ensure all inputs are traced back to the original extraction of raw materials.

All components were included where the necessary information was available or a reasonable estimate could be made. Components may have been omitted if their impacts were anticipated to fall well below 1% of the total system impacts. Labels and screws fall into this classification. The System Boundaries for each hand drying method under consideration are diagramed with key reference flows nearby.