Page 60 - Materials Chemistry, Second Edition

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2 Life-Cycle Assessment

2.1 INTRODUCTION

2.1.1 CONCEPT OF LIFE-CYCLE ASSESSMENT

Life-cycle assessment (LCA) of a product comprises the evaluation of the environ-
mental effects produced during its entire life-cycle, from its origin as a raw material
until its end, usually as a waste. This concept goes beyond the classical concept of
pollution from the manufacturing steps of a product, taking into account the
“upstream” and “downstream” steps. These steps can be illustrated by using the life-
cycle of a chair as an example.
Let us imagine that our chair would be manufactured in polished wood fixed by
iron screws, and that the seat would be made of a low-density foam layer covered
by polyamide fabric. If we carried out an evaluation of the chair based only on its
manufacturing stage, the study would show insignificant environmental impact. This
would be justified by the simplicity of the production process, in many cases reduced
to electricity consumption, dust generation and wood waste production due to the
assembly of all components. However, according to the life-cycle approach, we must
consider all the previous operations carried out in order to transform natural resources
into the intermediate products that will make up the chair. In this case, the study
would start with primary activities like wood planting, iron mining and crude oil
extraction and continuing through fabric manufacturing to the final assembly of the
chair. Moreover, we must include later stages such as use and final disposal from
the point of view of environmental impact. This means that we need to evaluate
each aspect related to natural resources consumption or waste releases from the
entire life-cycle of the chair. The most recognized and well-accepted method of
carrying out environmental assessment of products and services along their life-
cycles is the methodology of LCA. This chapter will present an overview of its
conceptual framework, common applications and importance for eco-design and
environmental management solutions.
In this framework, LCA is a tool to evaluate the environmental performance of
products (SETAC, 1993; UNEP, 1996). LCA focuses on the entire life-cycle of a
product, from the extraction of resources and processing of raw material through
manufacture, distribution and use to the final processing of the disposed product.
Throughout all these stages, extraction and consumption of resources (including
energy) and releases into air, water and soil are identified and quantified. Subse-
quently, the potential impact contribution of these resources’ extraction and con-
sumption, as well as environmental releases causing several important types of
environmental impacts, is assessed and evaluated (Curran, 1996; EEA, 1998).

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