Life-Cycle Assessment

Inventory Guidelines and Principles

Battelle Memorial Institute, Mary Ann Curran

• Publisher: CRC Press
• Year: 2020
• eBook ISBN: 9781000158106
• Topic: Technology & Engineering
• Subtopic: Electrical Engineering & Telecommunications
• Index: Technology & Engineering

Life-Cycle Assessment presents a brief overview of the development of the life-cycle assessment process and develops guidelines and principles for implementation of a product life-cycle inventory analysis. The book describes inventory analysis, impact analysis, and improvement analysis-the three components of a product life-cycle assessment. It discusses the major stages in a life cycle, including raw materials acquisition, materials manufacture, final product fabrication, filling/packaging/distribution, and consumer use and disposal.

Chapter One

INTRODUCTION

The concept of life-cycle assessment is to evaluate the environmental effects associated with any given activity from the initial gathering of raw material from the earth until the point at which all residuals are returned to the earth. This concept, often referred to as “cradle to grave” assessment, is not new. While the practice of conducting life-cycle studies has existed for more than 20 years, there has been no comprehensive attempt to describe the procedure in a manner that would facilitate understanding of the overall process, the underlying data, and the inherent assumptions. The literature contains few published assessments and even fewer peer-reviewed publications describing the technical basis for life-cycle assessments. The Society for Environmental Toxicology and Chemistry (SETAC) life-cycle assessment technical framework workshop report published in January 1991 summarizes the current status of the field and outlines the technical basis for life-cycle studies. The purpose of this U.S. Environmental Protection Agency inventory guidelines and principles document is to provide guidance on the specific details involved in the conduct of life-cycle studies.

Some of the most promising applications of life-cycle assessment are for internal use by corporations and regulatory agencies. By developing and using information regarding environmental effects that are both “upstream” and “downstream” of the particular activity under scrutiny, a new paradigm is created for basing decisions in both corporate management and regulatory policy-making.

Recently, there has been a sharp increase in the number of groups conducting life-cycle assessments. Often, the results of these studies have been used to support public claims about various products or processes. Predictably, the results of these studies are often in conflict, and somewhat dependent on the group sponsoring the study. With the increasing use of this information to gain a competitive advantage in the marketplace, there is a clear need for neutral, scientifically oriented, consensus-based guidelines on the conduct of life-cycle assessment.

The EPA has initiated a project to develop such guidelines. The project involves a multi-office EPA group devoted to addressing methodological issues concerning life-cycle assessments. This core group consists of representatives from the Office of Research and Development, Office of Solid Waste, Office of Air Quality Planning and Standards, and Office of Pollution Prevention and Toxics. This inventory guidelines document is the first in a series on conducting life-cycle assessment studies. Additional documents will follow as the knowledge and understanding of life-cycle assessment evolves. Near-term efforts include the preparation of documents that provide guidance on the impact analysis component, on data availability, and on data quality issues for life-cycle assessments. Improvement analysis and guidance for streamlining life-cycle studies are potential future products of this core group.

The EPA’s life-cycle assessment project includes using a consensus-building approach and working in close coordination with SETAC. As a scientific and professional society, SETAC has provided infrastructure, credibility, resources, and technical expertise to the development of life-cycle concepts both in the United States and internationally. Through the organization of a series of workshops, SETAC has overseen the development of an emerging technical framework for the conduct of life-cycle assessment.

Based on discussions at the 1990 SETAC workshop, life-cycle assessment consists of three components: inventory analysis, impact analysis, and improvement analysis. This document is intended to be a practical guide to conducting and interpreting life-cycle inventory analysis, which consists of an accounting of the resource usage and environmental releases associated with a product, process, or activity throughout each stage of its life cycle. Recently, the SETAC model has been expanded to include an initial step of goal definition and subsequent scoping analysis. These newer aspects of the SETAC model serve to tailor the scope and boundaries of life-cycle studies to be appropriate with the stated goals of the study. To the extent practicable, this document incorporates the concepts of goal definition and scoping as they apply to life-cycle inventory analysis.

Recent SETAC activity also has begun to define a conceptual framework for life-cycle impact analysis. Preliminary findings of this effort suggest that certain categories of impacts may require expanded or modified inventory data collection. To the extent that these requirements can be anticipated, this document incorporates the additional scope.

This document is not a “cookbook.” Given the range of applications, it is not feasible to provide “recipes” for every situation that could be encountered. Instead, this guide attempts to provide a rationale for ensuring internal consistency of procedures for both data acquisition and calculation used in life-cycle inventory analyses. This document relies heavily on practices that have been used by some life-cycle practitioners and that have evolved over many years. Certain decision rules in this guide are presented as specific recommendations because they have proven to be practical over their years of use. In other cases, where judgment is essential regarding an assumption in the study, the guide presents the relevant alternatives with some of the associated advantages and disadvantages. There is full recognition within this guide that the practice of life-cycle assessment continues to evolve. This guidance should be viewed as a starting point, capturing a “snapshot” of the state of the science of life-cycle inventory assessment. As the overall life-cycle assessment framework continues to evolve, it is very likely that changes to the inventory methods presented herein will be necessary.

Currently there is no single correct way to conduct a life-cycle assessment. One clear message of this document is that when a life-cycle practitioner makes assumptions or defines the boundary conditions of a life-cycle study, these decisions must be transparent to the users of that study. In other words, it is imperative for the credibility of the study that the goals, scope, and all assumptions inherent in any life-cycle study are clear to the audience for that study. It is recommended that all groups having a stake in the continued development and application of life-cycle assessment adopt the recommendations contained in this guide and fully disclose all of the assumptions used in the conduct of their life-cycle studies.

The guidance manual consists of five chapters. Chapter Two provide a methodology overview, including the status of current research and the basics of the life-cycle assessment methodology. Readers familiar with the concept may wish to skip this chapter. Subsequent chapters assume a considerable familiarity with the terms and concepts used for life-cycle studies. Chapter Three describes a technical framework for conducting a life-cycle inventory. Chapter Four discusses general issues in performing a life-cycle inventory. Chapter Five contains descriptions and analyses of issues pertaining to the individual stages and steps of a life-cycle inventory: raw materials acquisition; manufacturing (including materials manufacture, product fabrication, and filling/packaging/distribution); consumer use/reuse/maintenance; and recycle/waste management.

Chapter Two

OVERVIEW

LIFE-CYCLE ASSESSMENT CONCEPT

Over the past 20 years, environmental issues have gained greater public recognition. The general public has become more aware that the consumption of manufactured products and marketed services, as well as the daily activities of our society, adversely affect supplies of natural resources and the quality of the environment. These effects occur at all stages of the life cycle of a product, beginning with raw material acquisition and continuing through materials manufacture and product fabrication. They also occur during product consumption and a variety of waste management options such as landfilling, incineration, recycling, and composting. As public concern has increased, both government and industry have intensified the development and application of methods to identify and reduce the adverse environmental effects of these activities.

Major Concepts

• Life-cycle assessment is a tool to evaluate the environmental consequences of a product or activity holistically, across its entire life.

• There is a trend in many countries toward more environmentally benign products and processes.

• A complete life-cycle assessment consists of three complementary components: Inventory, Impact, and Improvement Analyses.

• Life-cycle inventories can be used both internally to an organization and externally, with external applications requiring a higher standard of accountability.

• Life-cycle inventory analyses can be used in process analysis, material selection, product evaluation, product comparison, and policy-making.

Life-cycle inventory is a “snapshot” of inputs to and outputs from a system. It can be used as a technical tool to identify and evaluate opportunities to reduce the environmental effects associated with a specific product, production process, package, material, or activity. This tool can also be used to evaluate the effects of resource management options designed to create sustainable systems. Life-cycle inventories may be used both internally by organizations to support decisions in implementing product, process, or activity improvements and externally to inform consumer or public policy decisions. External uses are expected to meet a higher standard of accountability in methodology application. Life-cycle assessment adopts a holistic approach by analyzing the entire life cycle of a product, process, package, material, or activity. Life-cycle stages encompass extraction and processing of raw materials; manufacturing, transportation, and distribution; use/reuse/maintenance; recycling and composting; and final disposition. It is not the intent of a life-cycle assessment to analyze economic factors. A life-cycle assessment can be used to create scenarios upon which a cost analysis could be performed.

The three separate but interrelated components of a life-cycle assessment include (1) the identification and quantification of energy and resource use and environmental releases to air, water, and land (inventory analysis); (2) the technical qualitative and quantitative characterization and assessment of the consequences on the environment (impact analysis); and (3) the evaluation and implementation of opportunities to reduce environmental burdens (improvement analysis). Some life-cycle assessment practitioners have defined a fourth component, the scoping and goal definition or initiation step, which serves to tailor the analysis to its intended use.

Life-cycle assessment is not necessarily a linear or stepwise process. Rather, information from any of the three components can complement information from the other two. Environmental benefits can be realized from each component in the process. For example, the inventory analysis alone may be used to identify opportunities for reducing emissions, energy consumption, and material use. The impact analysis addresses ecological and human health consequences and resource depletion, as well as other effects, such as habitat alteration, that cannot be analyzed in the inventory. Data definition and collection to support impact analysis may occur as part of inventory preparation. Improvement analysis helps ensure that any potential reduction strategies are optimized and that improvement programs do not produce additional, unanticipated adverse impacts to human health and the environment. This guidance document is concerned primarily with inventory analyses.

A BRIEF HISTORY OF LIFE-CYCLE INVENTORY ANALYSIS

Life-cycle inventory analysis had its beginnings in the 1960s. Concerns over the limitations of raw materials and energy resources sparked interest in finding ways to cumulatively account for energy use and to project future resource supplies and use. In one of the first publications of its kind, Harold Smith reported his calculation of cumulative energy requirements for the production of chemical intermediates and products at the World Energy Conference in 1963.

Later in the 1960s, global modeling studies published in The Limits to Growth (Meadows et al., 1972) and A Blueprint for Survival (Club of Rome) resulted in predictions of the effects of the world’s changing population on the demand for finite raw materials and energy resources. The predictions of rapid depletion of fossil fuels and climatological changes resulting from excess waste heat stimulated more detailed calculations of energy use and output in industrial processes. During this period, about a dozen studies were performed to estimate costs and environmental implications of alternative sources of energy.

A Life-Cycle Assessment Has Three Components

These components overlap and build on each other in the development of a complete life-cycle assessment.

• Inventory Analysis

• Impact Analysis

• Improvement Analysis

Scoping is an activity that initiates an assessment...

Table of contents

• Cover
• Title Page
• Copyright Page
• Foreword
• Abstract
• Table of Contents
• List of Figures
• Acknowledgments
• Summary and Index of Guiding Statements and Key Principles
• Chapter One Introduction
• Chapter Two Overview
• Chapter Three Procedural Framework for Life-Cycle Inventory
• Chapter Four General Issues in Performing a Life-Cycle Inventory
• Chapter Five Issues Applicable to Specific Life-Cycle Stages
• References
• Glossary
• Appendix