ental emissions of the product and its manufacturing process are quantified. Precise and extensive calculations are involved in this step. Totals for all material requirements and environmental emissions are presented for all stages of production, from raw materials acquisition to waste management.
The third step is an impact assessment, which attempts to translate the life-cycle inventory data into effects on human health, ecological health, and resource depletion, which are the impacts of the product and its manufacturing process on the environment. The impact assessment is accomplished by classifying the inventory items into condition groups that may lead to an environmental impact.
The final step in a life-cycle assessment is an improvement analysis. The improvement analysis develops recommendations based on the results of the life-cycle inventory and the life-cycle impact assessment. Such recommendations may include the modification of a production process, the use of different raw materials, or choosing one product over another, as is the case in this current study.
The steps of the life-cycle assessment process from life-cycle inventory through life-cycle improvement analysis are addressed in this current study in the following two sections. In these two sections, these steps of the life-cycle assessment process are developed for both plastic bags and paper bags.
The life-cycle assessment of plastic bags is presented in relation to life-cycle inventory, life-cycle impact assessment, and life-cycle improvement analysis.
The life-cycle inventory analysis is a technical, data-based process of quantifying energy and raw material requirements, atmospheric emissions, waterborne emissions, solid wastes, and other releases for the entire life cycle of a product, package, process, material, or activity. In this section, the life-cycle inventory is developed for plastic bags.
In the broadest sense, a life-cycle inv...