ABSTRACT
This chapter discusses the issues specific to each of the four life-cycle stages, i.e., raw materials and energy acquisition, manufacturing, use/reuse/maintenance, and recycle/waste management. The life cycle of any product or material begins with the acquisition of raw materials and energy sources. A typical life-cycle inventory of a product evaluates the primary product and may include associated primary, secondary, and tertiary packaging. Resource requirements that can be quantified should be included in the life-cycle inventory. Statistics are available that quantify such effects as pesticide runoff from agricultural activities, brine production from oil wells, waterborne wastes from animal feed-lots, etc. In a life-cycle inventory, energy requirements of a system are not reduced or credited for the use of “renewable” resources instead of “nonrenewable” resources. In a life-cycle inventory analyzing the use of an animal product, the feed to produce the animal product usually is considered to be the main raw material for the system.
