EPA/600/R-11/107
September 2011
Guidance to Facilitate Decisions for
Sustainable Nanotechnology
Authors
Tarsha Eason
David E. Meyer
Mary Ann Curran
Venkata K.K. Upadhyayula (ORISE)
Systems Analysis Branch
Sustainable Technology Division
National Risk Management Research Laboratory
Cincinnati, Ohio 45268
National Risk Management Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
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The U.S. Environmental Protection Agency through its Office of Research and Development
funded, managed, and collaborated in the research described here under EP-W08-010 to Abt
Associates, Inc. It has been subject to the Agency's review and has been approved for
publication as an EPA document.
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The U.S. Environmental Protection Agency (EPA) is charged by Congress with protecting the
Nation's land, air, and water resources. Under a mandate of national environmental laws, the
Agency strives to formulate and implement actions leading to a compatible balance between
human activities and the ability of natural systems to support and nurture life. To meet this
mandate, EPA's research program is providing data and technical support for solving
environmental problems today and building a science knowledge base necessary to manage our
ecological resources wisely, understand how pollutants affect our health, and prevent or reduce
environmental risks in the future.
The National Risk Management Research Laboratory (NRMRL) is the Agency's center for
investigation of technological and management approaches for preventing and reducing risks
from pollution that threaten human health and the environment. The focus of the Laboratory's
research program is on methods and their cost-effectiveness for prevention and control of
pollution to air, land, water, and subsurface resources; protection of water quality in public water
systems; remediation of contaminated sites, sediments and ground water; prevention and control
of indoor air pollution; and restoration of ecosystems. NRMRL collaborates with both public and
private sector partners to foster technologies that reduce the cost of compliance and to anticipate
emerging problems. NRMRL's research provides solutions to environmental problems by:
developing and promoting technologies that protect and improve the environment; advancing
scientific and engineering information to support regulatory and policy decisions; and providing
the technical support and information transfer to ensure implementation of environmental
regulations and strategies at the national, state, and community levels.
This publication has been produced as part of the Laboratory's strategic long-term research plan.
It is published and made available by EPA's Office of Research and Development to assist the
user community and to link researchers with their clients.
Sally Gutierrez, Director
National Risk Management Research Laboratory
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Products that incorporate materials manufactured at the nano scale (i.e., nanoproducts) offer
many potential benefits to society; however, these benefits must be weighed against potential
"costs" to the environment and public health. This document was developed to provide a broad
guidance for assessing the sustainability of nanoproducts and is intended to lay the groundwork
for developing a decision-support framework through continual updates as research in this area
progresses. At the very least, it will aid stakeholders when navigating the various choices that
must be made to foster the development of sustainable nanotechnology. Given the all-
encompassing nature of sustainability, this work should be of interest to stakeholders in all areas
of nanotechnology, including research, product development, consumer use, and regulation. The
aim of this work is not to make decisions for stakeholders, but to help frame the pertinent issues
that must be addressed to properly assess emerging nanotechnologies and to provide information
on the various tools that may be used to address them. The foundation of this approach is to
consider existing standards and methods for environmental, economic, and social assessments
using a life cycle perspective and offer guidance by relaying first-hand knowledge of applying
assessment tools to nanotechnologies, whenever possible. Brief overviews of the various
assessment methodologies are provided to help stakeholders make informed choices when
selecting tools appropriate for their goals. For specific details of a method, readers are directed to
the referenced standards and guidance documents supporting the application of these tools. The
key steps to be included in the evolving framework include: characterizing a nanoproduct and
identifying potential risks and impacts; identifying relevant stakeholders; defining the goal and
scope of an assessment; assessing environmental, economic, and social impacts; evaluating
sustainability criteria; developing and evaluating alternatives; and selecting and implementing a
decision to support sustainability. Given that the field of nanotechnology is relatively new, there
are significant uncertainties regarding its potential human health and ecological risks and impacts.
Hence, methods developed to address these uncertainties are also explored. Moreover, since the
field of nanotechnology is changing rapidly, this document will be reviewed and updated as
additional information becomes available to continue working towards the end goal of
sustainability.
IV
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Notice ii
Foreword iii
Abstract iv
Figures and Tables vi
1. Managing Sustainable Nanotechnology 7
1.1 Nanotechnology Overview 7
1.2 Towards Sustainability 8
1.3 Document Overview 10
1.4 Key Benefits to the Intended Audience 14
2. Initializing the Path Forward to Sustainability 15
2.1 Initial Product Characterization and Identification of Potential Risks 16
2.2 Stakeholder Identification 19
2.3 Goal and Scope Definition 20
3. Assessing Environmental, Economic, and Social Impacts 25
3.1 Environmental Assessment Methods 25
3.2 Economic Assessment Methods 39
3.3 Social Assessment Methods 46
4. Assessing Sustainability 51
4.1 Evaluating Sustainability Criteria 51
4.2 Decision Theory 54
4.3 Selecting the Most Sustainable Alternative 58
4.4 Uncertainty Analysis 63
4.5 Sensitivity Analysis and Scenario Analysis 63
4.6 Further Analysis 64
5. Conclusions 65
6. Acknowledgements 65
7. References 66
Appendix: List of Additional Resources 75
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Figure 1-1. A Holistic View of Sustainability 8
Figure 1 -2. Overview of a Preliminary Framework for Sustainable Nanotechnology 13
Figure 2-1. Identifying Risks Early in the Process 17
Figure 2-2. Example of Stakeholder Mapping 19
Figure 2-3. Sample Goal and Scope definition: The life cycle of a pair of cotton socks containing
antimicrobial silver 24
Figure 3-1. General Framework for a Product Life-Cycle Assessment (LCA) 29
Figure 3-2. Nano Risk Framework 31
Figure 3-3. Life-Cycle Costing (as presented in SETAC) 42
Figure 3-4. Social Life-Cycle Assessment 47
Figure 4-1. Mapping the Decision Criteria: Sample Criteria for Assessing Single-Walled Carbon
Nanotube Synthesis Processes 52
Figure 4-2. Decision Analysis Flowchart 55
Figure 4-3. Modified Decision Analysis (DA) Approach 56
Figure 4-4. Comparison of Single Walled Carbon Nanotubes (SWCNT) Criteria Weightings.... 63
Table 2-1. Traditional Product Development and Sustainable Design proceed 16
in tandem and entail overlapping steps 16
Table 2-2. Identifying Risks Early in Development 18
Table 2-3. Examples of Sustainability Criteria 21
Table 3-1. Key Environmental Assessment Methods 26
Table 3-2. Key Economic Assessment Methods 43
Table 3-3. Example Factors Impacting Incumbent Firms 45
Table 3-4. Key Social Assessment Methods 48
Table 4-1. Sample Decision Making Tools 53
Table 4-2. Comparison of Process Elements for Common Decision Making Tools 57
Table 4-3. Summary of Common Multi-Criteria Decision Analysis (MCDA) Methods 59
VI
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1. Managing Sustainable Nanotechnology
1.1 Nanotechnology Overview
The U.S. National Nanotechnology Initiative (NNI) defines a technology as nanotechnology
only if it involves all of the following:
• Control or manipulation of matter at dimensions in the 1 to 100-nanometer range.
• Creation of structures, devices and systems that have unique properties and functions at
the nanoscale leading to novel applications.
Nanotechnology relates to the ability to create materials and devices through the manipulation of
individual atoms and molecules (up to 100 nanometers). Further, it involves integrating these
structures into larger systems (Bhushan, 2007). Similar to information technology,
nanocomponents (the nanoscale building blocks of nanotechnologies) exhibit a diverse array of
characteristics that may be used for a wide range of beneficial applications and have the potential
to generate significant improvements to existing technologies (Palmberg et al., 2009). These
applications include medical, food, clothing, defense,
national security, environmental clean-up, energy
generation, computing, construction, and electronics
(Davies, 2009; EPA-SPC, 2007). Consequently,
according to a recent publication from the Organization
for Economic Co-operation and Development (OECD),
the field of nanotechnology is rapidly expanding
(Wiesner et al., 2006) and is anticipated to emerge as a
key engine of growth for the 21st century (Palmberg et
al., 2009).
Throughout this framework, the diverse products and materials that are made using (engineered)
nanocomponents will be collectively referred to as nanoproducts.
Nanotechnology is being touted as a profound
technological advancement capable of transforming
society as we know it. Accordingly, the investment in
nanotechnology initiatives have skyrocketed (Roco,
2009). However, the potential for explosive growth in
nanoproduct markets should be viewed with cautious
optimism. Without question, knowledge of the physical
world at the nanoscale opens a world of possibilities to
enable the development of products and systems with
great precision and intricate properties that could improve
our overall quality of life. Systematic control of the
production of products at the molecular level could enable
the development of eco-friendlier products and services. The projected trillion-dollar
nanotechnology market is expected to provide new markets, create jobs, and greatly increase
profits for businesses. However, caution must be applied to temper these expectations when
considering the growing concerns regarding the unforeseen impacts of nanotechnology
deployment. For example, with many nanotechnologies requiring energy intensive processes and
rare materials, it is unclear how large-scale deployment will affect the environment. In addition,
the cost needed to retrofit production and incorporate nanotechnology may be more than some
"IfI were asked for an area of
science and engineering that will
most likely produce the
breakthroughs of tomorrow, I
would point to nanoscale science
and engineering."
Neal Lane
Former NSF Director
Assistant to President Clinton
for Science and Technology
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existing companies can afford. This could lead to a radical shift in the make-up of the various
application markets, resulting in the emergence of corporate monopolies and destabilization of
the global economy. In addition, the more advanced manufacturing processes will require
workers with greater knowledge and expertise, thereby putting pressure on the existing workforce
to adapt mentally or risk unemployment, a problem that can quickly alter societal dynamics.
Perhaps the greatest concern with nanotechnology is the potential threat that nanocomponents
pose to human health and ecosystems. NSF's increasing investment in the safety and societal
implications of nanotechnology (Roco, 2009) stems from recognition that the unique properties
that define a nanotechnology and make it novel are the same properties that could eventually pose
the greatest health risks. These various concerns transcend the science of nanotechnology and
raise the issue of its sustainability.
1.2 Towards Sustainability
The National Environmental Policy
Act of 1969, a precursor to the
establishment of the Environmental
Protection Agency, formalized a
growing understanding of the
importance of the relationship
between humans and the
environment. Further its language,
"... to declare a national policy Figure 1-1. A Holistic View of Sustainability
which will encourage
productive and enjoyable harmony between man and his environment; to promote efforts which
will prevent or eliminate damage to the environment and biosphere and stimulate the health and
welfare of man....", foreshadows ideals soon to be of great importance on a global stage. Nearly
two decades later, the World Commission on Environment and Development (WCED) coined the
term sustainable development as "development that meets the needs of the present without
compromising the ability of future generations to meet their own needs" (ONGO, 1987). Thus,
sustainability may be viewed as using resources and developing products and processes in a way
that ensures and promotes a legacy of economic viability, social equity and environmental
responsibility for current and future generations.
Many researchers recognize that traditional growth and development practices are contradictory
to shifting to a sustainability paradigm (2003). While there is great interest in this area, some
believe that economic progress and sustainability are mutually exclusive (Davidson and Julie,
2001). This idea is birthed from the concept that sustainable development inevitably translates
into benefiting one facet to the detriment of another. However, in truth, it is about balance and
optimization and entails evaluating the intricate elements of sustainability (Berkel, 2000; Eason et
al., 2009). Built on a foundation of economic, social and environmental indicators, sustainability-
based decision making is a highly complex challenge and is predicated on the ability to reconcile
both disparate and integrated aspects of the product, process, or system under study. Given the
magnitude of its anticipated impact, nanotechnology should therefore be produced and utilized in
a manner that is environmentally, economically, and socially sustainable to fully realize its
potential (Helland et al., 2007; Klopffer, 2008).
Years after the WCED definition was accepted, researchers have continued to struggle with
reaching a consensus on how sustainability should be measured. However, one key development
and widely accepted convention was to establish what is termed the three pillars of sustainability:
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environment, economy, and society (Figure 1-1). Each of these pillars denotes particular aspects
of the product, process, or system that may be assessed via observable and measurable criteria
(i.e., metrics). While there are tools available that may be used to evaluate characteristics within a
particular pillar, the difficulty lies in making decisions based on information gathered from
various tools and disparate criteria.
The challenge of sustainability begins with an understanding of the holistic nature of the world in
which we live. Traditional Newtonian
thinking views the world as isolated
subsystems and seeks solutions to problems
within each system with little regard to
how the various systems interact. In
contrast, holistic thinking examines how
changes within a subsystem can affect the
system as a whole through interactions
across subsystem boundaries, recognizing
that the world is an integrated sum of its
parts. This holistic approach has inspired
the field of industrial ecology, a systems-
based, multidisciplinary approach to
understand the emergent behavior of
complex integrated human/natural systems.
With nanotechnology, it is important to
understand how the various world systems
(i.e., ecosystems, societies, etc.) will be
impacted by its existence throughout its full
life span (i.e., from cradle to grave). The
life cycle concept identifies five key stages
where impact may occur, including:
Raw materials extraction: Activities related to the acquisition of natural resources,
including mining non-renewable material, harvesting biomass, and transporting raw
materials to processing facilities.
Materials processing: Processing of natural resources by reaction, separation,
purification, and alteration steps in preparation for the manufacturing stage; and
transporting processed materials to product manufacturing facilities.
Product manufacture: Manufacture of product and transport to the consumers.
Product use: Use and maintenance activities associated with the product by the
consumer.
End-of-life disposition: Disposition of the product after its life span, which may include
transportation, recycling, disposal, or incineration.
Systems Thinking
In his landmark book, The Fifth Discipline,
Peter Senge wrote, "From a very early age, we
are taught to break apart problems, to segment
the world. This apparently makes complex tasks
and subjects more manageable, but we pay a
hidden price. We can no longer see the
consequences of our actions; we lose our
intrinsic sense of connection to a larger whole."
For Senge, the answer lay in systems thinking.
Applying systems thinking helps creative
individuals to see wholes, perceive
relationships, uncover connections, expose root
causes and master complexity. Senge argued
that systems thinking integrates what might
otherwise be considered separate management
disciplines, preventing them from becoming
"gimmicks or the latest organisation change
fads." (Smith, 2005)
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The Daly Rules for Sustainability
Working from theory initially developed by Romanian economist Nicholas Georgescu-Roegen,
Herman E. Daly (University of Maryland School of Public Policy professor and former Chief
Economist for the World Bank), laid out in his 1971 opus "The Entropy Law and the Economic
Process") suggests the following three operational rules for defining the condition of ecological
(thermodynamic) Sustainability:
1. Renewable resources such as fish, soil, and groundwater must be used no faster than
the rate at which they regenerate.
2. Nonrenewable resources such as minerals and fossil fuels must be used no faster than
renewable substitutes for them can be put into place.
3. Pollution and wastes must be emitted no faster than natural systems can absorb them,
recycle them, or render them harmless.
Accordingly, each stage during product development should be optimized to minimize the
impacts within the three pillars. However, it is important to remember that changes to one stage
can lead to impacts in another stage. Thus, the holistic approach is needed to achieve
Sustainability. True Sustainability, as described by Daly (text box above), may never be fully
achieved during a product's life cycle in the short term. Subsequently, the goal of sustainable
development would be to help identify the most desirable option based on available technologies
and current industrial practices. However, it is beneficial for decision makers to remain open and
continually explore alternative solutions for a product function by periodically revisiting the
design and manufacture of a product. Potential product alternatives can provide a comparative
basis to better understand assessment results. In some cases, the alternative may be an existing
product or process and in others, after the initial design, it may be worthwhile to generate
alternatives encompassing other available technologies.
1.3
This document presents guidance for integrating Sustainability into the evaluation, management
and development of nanoproducts. The material is presented while keeping in mind the long term
goal for this work to eventually be refined into a decision support framework. It is intended to
support Goal 4 of the NNI's Strategic Plan "to support the responsible development of
nanotechnology"(NNI, 2011). Efforts in this area are coordinated by the Nanotechnology
Environmental and Health Implications (NEHI) working group of the Nanoscale Science,
Engineering, and Technology (NSET) Subcommittee that maintains the Environmental, Health,
and Safety (EHS) research strategy. Since the original EHS research strategy was written in 2008,
the NEHI has collaborated with stakeholders from government agencies, industry, academia, non-
governmental organizations (NGOs) and the general public to determine how best to update and
improve EHS research (NNI, 2010). One of the primary results of these actions was the
recognition of the stakeholders to incorporate life cycle considerations for Sustainability into risk
management for nanocomponents and nanoproducts. Therefore, the preliminary framework of
this guidance represents a reasonable approach to Sustainability assessment rooted in a life cycle
perspective.
Since anyone involved with the life cycle of a product may constitute a stakeholder (Freeman,
1984; Mitchell et al., 1997), the guidance that follows is intended to provide researchers, product
developers, NGOs, policy makers, and consumers with an understanding of the various choices
10
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that must be made to ensure the development and sustainable use of nanoproducts. While some
may argue that control of product sustainability is ultimately in the hands of researchers and
product developers, it is important that stakeholders throughout the product life cycle have a
common understanding of the benefits and challenges associated with sustainability in order to
better work together to achieve it. Further, this guidance helps stakeholders understand the tools
that may be used to assess aspects of sustainability and identifies current approaches in the
literature to attempt to integrate data from these disparate evaluations to make quality decisions.
At present, integration of assessment tools is a key challenge for sustainability assessment in
general with no clear consensus choice of method available. As an additional benefit to
stakeholders, discussions of potential pitfalls and areas of concern that may arise during
assessment are included. Moreover, whenever possible, the authors relay first-hand knowledge of
the application of specific assessment tools to nanoproducts.
The guidance offered in this document may be applied to both new and existing technologies. An
existing nanoproduct can be a complete product redesign, a modification of an existing
nanoproduct, or the incorporation of nanotechnology into a traditional consumer product.
However, the large number of unknowns regarding the use and disposal of nanomaterials makes
it more challenging to successfully address the critical sustainability concerns within the life
cycle of a new nanoproduct or concept prior to full-scale implementation. Therefore, researchers
and product developers must integrate sustainability considerations into subsequent modifications
to correct for unforeseen issues as the nanoproduct evolves and develops. For the sake of
discussion, guidance is presented for the case of new technology development with the
understanding that any issues that may arise when dealing with product redesign can be addressed
using the same principles.
Before presenting the preliminary framework that will guide the discussions in this document, it
is important to first recognize a key contribution to life cycle based sustainability assessment in
the open literature to provide readers with an understanding of why this work has chosen to adopt
a different approach to accomplish decision making for sustainable nanotechnologies. Kloepffler
(2008) has proposed Life Cycle Sustainability Assessment (LCSA) as a tool to evaluate the
sustainability of products. The tool integrates the existing methods of Life Cycle Assessment
(environment), Life Cycle Costing (economy) and Social Life Cycle Assessment (society) to
perform a sustainability assessment using the existing indicators of each method for the
respective pillars. While this approach is a viable option, it presupposes the ability of these three
tools to account for all potential implications of a product. As will be presented in this document,
there are many challenges associated with assessing nanotechnology that may fall outside of the
scope of these three tools. Therefore, this work will focus on developing a framework that is more
readily adaptable for nanoproducts by allowing for a customizable selection of indicators, and
therefore tools to be made by those with first-hand knowledge of the product/system to be
studied. This should lead to more relevant decisions regarding the development of sustainable
nanotechnologie s.
Figure 1-2 demonstrates how the preliminary framework presented in this guidance document can
be deployed during product development. Experts can include risk assessors, economists, public
health experts, or other scientists that may offer important advice in assessing impacts and
selecting approaches for mitigating these impacts. The people who will guide the overall
application of the framework are a group of decision-makers typically comprised of experts and
stakeholders. The key steps of the framework include:
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1. Characterize product and identify potential health and environmental (toxicity)
risks. At the outset of developing the initial idea or product concept, product
developers should conduct an initial characterization of the potential health and
environmental (toxicity) risks of the chemicals contained in the product. This would
allow the team to identify and mitigate potential chemical hazards early on in the
product design stage.
2. Identify stakeholders. Stakeholders should be identified early and engaged at the
outset of sustainability assessments, as they provide important input in defining the
goal and scope of the study, as well as helping to develop appropriate sustainability
metrics, evaluating and interpreting impacts, and selecting alternative approaches to
mitigate impacts.
3. Define assessment goal and scope. Establish the goals and objectives of the
analysis and determine the appropriate methods and models to meet the assessment
objectives. This step involves translating the broad concept of sustainability into
concrete, measurable goals, which can be assessed in step 4.
4. Assess environmental, economic, and social impacts: Apply methods for assessing
environmental, economic, and social impacts across the life cycle of the nanoproduct.
These impacts include, but are not limited to: energy and material use, costs to the
manufacturer, greenhouse gas emissions, and wages. Uncertainty should be assessed
and a sensitivity analysis may be conducted as part of this step.
5. Evaluate sustainability criteria. Normalizing the inventory of impact results into
pertinent categories related to the sustainability criteria and eliciting stakeholder
valuations of criteria to interpret and compare results.
6. Develop alternative approaches to mitigate impacts. The results of the
assessments and evaluations can help developers identify improvements to the
product system that will mitigate impacts (e.g., modification to the manufacturing
process or use of alternative nanomaterial in an upstream process).
7. Assess the environmental, economic, and social impacts of the alternative
approaches. Each alternative approach developed should be assessed to determine
the impacts for each pillar. The results will then be used to compare different
alternatives. As part of this step, additional alternatives may need to be developed
and assessed if the initial designs are found to be inadequate for improving the
sustainability of the product.
8. Select most sustainable alternative. Once the environmental, social, and economic
impacts for each alternative are assessed, decision makers work together to select the
best alternative approach for mitigating impacts and achieving a sustainable product
design.
9. Implement production of sustainable nanoproduct. Following selection of the
preferred alternative, the product should be manufactured and continually monitored
for further improvements using the sustainability framework.
Although these steps are discussed with regard to a new product development, we re-emphasize
that the framework may also be applied to products in any development stage, including those
that are already commercialized. As noted above, achieving sustainability is an iterative process
in that products should be continually assessed and updated as new information becomes
available. The guidance in this document will be given through detailed discussion of each step of
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Sustainable Nanoproduct Concept
Characterize Product and
Identify Potential Risks
Section 2.1
Identify Stakeholders
Section 2.2
Environmental
Assessment
Section 3.1
Define Assessment
Goal and Scope
Section 2.3
Economic
Assessment
Section 3.2
Evaluate Sustainability
Criteria
Section 4.1
Select Most Sustainable
Alternative
Section 4.2
Implement Sustainable
Nanoproduct
Social
Assessment
Section 3.3
Develop
Alternatives
Redevelop product
concept as
technology improves
Figure 1-2. Overview of a Preliminary Framework for Sustainable Nanotechnology
the preliminary framework and is presented in Sections 2-4. Section 5 presents overall
conclusions of this work and how they can be applied to refine the proposed framework. Finally,
the Appendix includes a list of additional resources that may be useful in conducting
sustainability assessments of nanoproducts.
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1.4 to the
As previously described, this document is anticipated to primarily assist nanotechnology
researchers, developers, engineers, and product manufacturers in addressing potential
environmental, economic, and social implications throughout the life cycle stages of a new or
developing nanoproduct. It can also be useful to other decision-makers, including government
agencies and NGOs by providing a better understanding of the pertinent issues that must be
addressed to properly assess the sustainability of a nanotechnology.
Industry and government stakeholders can realize many benefits from conducting and supporting
sustainability assessments of nanoproducts. A sustainability assessment can contribute to research
that will aid current efforts to promote health and safety when manufacturing nanoproducts as
well as in their public use or consumption. This will not only help minimize risk, but also reduce
unsubstantiated or nonscientific claims of risks or benefits of nanoproducts. Further, if
nanoproduct developers can demonstrate that they are serious about developing a sustainable
product that presents minimal long-term risks to human health and the environment, then their
products may be viewed more favorably. Such an effort will help avoid an inaccurate perception
of risks among the general public similar to those that arose for genetically modified organisms
(Bell, 2007). Upon completion, this process will aid in establishing a protocol toward the
development, management and assessment of sustainable nanoproducts. Additionally, it will
provide life cycle data (material and energy flows) that may be used as a benchmark for future
sustainability assessments of nanoproducts and technologies, to measure improvements, and
evaluate the impacts of possible design changes.
Other benefits include:
• Placing human health risk assessment in perspective with other environmental concerns
across the life cycle of nanoproducts.
• Quantifying energy and resource intensive processes and minimizing their impact.
• Identifying cost savings for the manufacturer and consumer.
• Developing an evaluation of impacts and risks to human health, the environment, and
society from the local to national and global scales.
• Demonstrating a commitment by manufacturers to stakeholders for the responsible
development of nanoproducts.
Notice of Use
Any comparisons discussed in this document refer to internal comparisons within a
company's own processes or alternatives. Internal comparisons can help a
company to improve an existing product line, but do not make any claims in
regards to other companies' products. Comparing products against similar
products from other companies and making a public statement about results,
known as a comparative assertion, requires a thorough review process, which
is not presently addressed.
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2. Initializing the Path Forward to Sustainability
Before offering detailed guidance based on the preliminary framework, it is important to
articulate how sustainability can be integrated into existing models of product deployment.
Product deployment is comprised of two stages, product development and product management.
Traditionally, product development can be broken down into a series of steps including:
• Idea Generation: Use brainstorming to identify potential products and markets.
• Idea Screening: Eliminate impractical ideas and select most promising alternative.
• Concept Development and Testing: Establish engineering and marketing details.
• Business Analysis: Use stakeholder feedback to estimate pricing and profitability.
• Beta Testing and Market Testing: Produce prototype and evaluate typical use.
• Technical Implementation: Develop quality guidelines for manufacturing; compile
product data sheets; prepare supply chain for product deployment.
• Commercialization: Product launch into consumer markets.
At the onset of commercialization, product management is invoked to oversee the product life
cycle. In this case, the term "life cycle" from a business perspective is different from what is
defined for sustainability and describes the four stages involved with marketing a product: (1)
Introduction, (2) Growth, (3) Maturity, and (4) Decline. These stages track the market penetration
of a product and its consumer acceptance. Upon entering the Decline stage, businesses can either
discontinue a product or seek to redevelop it to make it commercially viable.
To achieve development of sustainable technologies and products, careful consideration must be
given to the issues of sustainability prior to commercialization and product management.
However, this is not as simple as inserting a "Sustainability Assessment" step into the product
development concept above. Instead, the steps of the sustainability framework described in this
document will have to move in tandem with the steps of product development as the needed data
become available. This will help insure that sustainability is achieved for a product in a manner
that maximizes its benefits to a company while minimizing its impact on the process of product
deployment.
The overlap of sustainability with product deployment is shown in Table 2-1. Sustainability
concerns are not considered during the generation of ideas to avoid stifling creativity. As a
product idea develops, sustainable design begins with consideration of the basic risks and
eventually grows into full assessment of the three pillars. However, the various pillars can and
should be considered at multiple times throughout product deployment to maximize the potential
for sustainability. For example, the environmental impacts of manufacturing and distributing a
proposed product can be examined during concept development and testing using pilot scale data
and engineering estimations. Once beta testing is initiated, this assessment can be revisited and
expanded to include the use and disposal phase based on testing results. The data can be updated
using realistic manufacturing data during technical implementation. Finally, the environmental
impacts can be reassessed during product management using real market data to identify any
potential concerns that did not manifest themselves during design. This approach is intended to
provide companies ample opportunity to amend a product to achieve sustainability goals prior to
large scale commercialization through early detection and action. Thus, sustainable design from a
business perspective is both iterative and cyclic in nature. By keeping this in mind, it will be
easier to understand the discussions of assessment and decision-making tools that follow.
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Table 2-1. Traditional Product Development and Sustainable Design proceed
in tandem and entail overlapping steps
Product Development Sustainable Design
Idea Generation
Idea Screening
Concept Development and
Testing
Business Analysis
Beta Testing and Market Testing
Technical Implementation
Commercialization
Product Management
Initial Risk Screening
Product Characterization, Risk Screening, Stake
Holder Identification, Environmental Assessment
Economic Assessment and Social Assessment
Product Characterization, Risk Screening,
Environmental Assessment
Risk Screening, Environmental Assessment
Economic Assessment and Social Assessment
Risk Screening, Environmental Assessment,
Economic Assessment, Social Assessment
2.1 Initial Product Characterization and Identification of Potential Risks
Defining the Nanoproduct Concept
1. What is the function of this product?
2. What is the anticipated target market?
3. What are the necessary materials?
4. Is there more than one approach?
One of the first steps of the framework is to
appropriately characterize the nanoproduct. This
includes an understanding of how the product
will be used along with a general description of
the intended materials and characteristics (e.g.,
chemical composition, physical form/shape,
solubility, state of aggregation or agglomeration,
etc.), and physical and mechanical properties.
Characterization of the product should be
detailed enough to provide sufficient guidance for conducting an analysis throughout the
product's life cycle stages. When characterizing the nanomaterials, the reader can refer to the
International Organization for Standardization's report on the classification and characterization
of nanomaterials (ISO, 2010).
Before undertaking a full sustainability assessment, it is appropriate to determine whether easily
identifiable risks are present and whether they can be mitigated (Figure 2-1). This action is not
intended to be a full risk assessment as defined in Chapter 3. Instead, it should be a quick
screening-level identification of known risks. For example, if a proposed electronic product will
involve lead or other toxic metals as part of the circuitry, the known risks related to exposure to
these materials should be addressed before continuing. A benefit of this type of screening-level
risk identification is that it can lead to the development of better products that are more
sustainable. However, this may be more a challenging task when quickly considering
nanoproducts because of the general lack of knowledge regarding the associated risks of
nanomaterials. Although the toxicity and risk related to nanomaterials and products continues to
be investigated, recent studies have found a correlation between certain physicochemical
properties of nanomaterials and their potential toxicities. For example, the size and shape of a
nanomaterial influences deposition patterns in the human respiratory tract. Nanomaterials that are
deposited in the respiratory tract may cause symptoms similar to those caused by asbestos (e.g.,
16
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immune-system malfunction, lung disease, and cell inflammation) (Olapiriyakul and Caudill,
2008). Other characteristics of nanomaterials that may affect toxicity include the chemical
composition, aspect ratio, crystal structure, surface area, surface chemistry and charge, solubility,
adhesive properties, and emergent properties (Klopffer et al., 2007). It has generally been found
that if nanomaterials are embedded as part of larger objects (e.g., nanocomposites and
nanocrystalline solids) they are less dispersive and present lower risk than if they are used as free
nanoparticles, nanorods or nanofibers (Ostertag and Husing, 2008). In addition, recent research
focused primarily on airborne pathways has examined the hazards associated with exposure to
nanomaterials in the workplace. These studies have found that some nanomaterials damage lung
tissue after inhalation (Wiesner et al., 2006). The potential risk of such exposure will depend on
how the nanocomponents are produced and handled while being incorporating into nanoproducts.
A study by Sengul, et al. (Sengul et al., 2008) provides a comprehensive review of techniques
used to manufacture nanoproducts, a description of the technique, key processes, materials used,
primary energy consumption, and environmentally significant aspects. These techniques include
top-down approaches where nano-scale dimensions are achieved through carving or grinding
(e.g., lithography, etching, electro-spinning, and milling), or bottom-up methods in which
nanomaterials are developed at the atomic scale using vapor-phase, liquid-phase, and self-
assembly techniques (Sengul et al., 2008).
Characterize product and identify potential risks
Characterize product
and identify
potential risks
Initial product
characterization
identifiable
potential
Yes
Implement
measures to
mitigate risks
Consult
regulatory
authorities
Figure 2-1. Identifying Risks Early in the Process
As shown in Figure 2-1, if easily identifiable potential risks are found, the product developers
should consult the appropriate regulatory authorities to determine whether there are any
compliance issues relevant to the nanomaterial or nanoproduct. In 2007, EPA convened a
workgroup to discuss and document the science needs associated with nanoproduct. The resulting
"Nanotechnology White Paper" (EPA-SPC, 2007) includes an overview of environmental statutes
that may be applicable to nanoproducts (e.g., Toxic Substances Control Act (TSCA), Clean Air
Act (CAA), and Clean Water Act (CWA)). EPA policies and regulations are evolving as research
on nanotechnology and its impacts continue and additional information becomes available.
However, measures should be taken to mitigate any easily identifiable risks and ensure
compliance with the current and appropriate regulations before taking further steps in
sustainability assessment. Examples of preliminary data needed to characterize early stage risks
of nanoproducts are given in Table 2-2. Although many sources are working to provide an
understanding of the potential toxicity of nanomaterials, nanomanufacturers should be
encouraged to incorporate toxicity studies if possible into their product development because the
17
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Table 2-2. Identifying Risks Early in Development
Nanomanufacturing
Are data available on the toxicity of the nanomaterials to
human health or organisms in the environment?
Are data available (pilot plant) on potential air
emissions, waste discharges and amounts of solid waste
generated?
Is any risk issues associated with release of these waste
streams? If yes, can the risk be contained with state of
the art treatment protocols available to treat air
pollutants/ liquid waste and solid waste?
Nanoproduct Use
Is there an anticipated release and transport of
nanomaterials from the nanoproduct during use?
Nanoproduct End Of Life
(EOL)
• What is the likely frequency of waste generated?
• Is nanomaterial encapsulated, semi dispersed or
loosely formulated in the product at its end of life?
• What are the effects of nanomaterials on
environment when incinerated or landfilled?
A Case Study in Early Intervention
In the early 1980s, I was working In the plastics industry as the head of health, safety, and environment for a major
business division of a parent company. Researchers at the division had just discovered a thermosetting catalyst that
was unlike any previously available. Epoxy-type resins begin curing at the moment they are mixed with standard cata-
lysts. This new catalyst remained inactive until a very specific and desirable temperature was reached.
This catalyst had enormous potential, and the marketing department immediately began distributing samples of
it in order to encourage commercial trials. But there were also indications of problems with the substance. Both my
department and the division's medical department recognized that the catalyst contained small amounts of a material
that potentially could be toxic under certain circumstances.
Jointly, we formed an internal task force consisting of toxicology, environmental, industrial hygiene, and medical
professionals. Our work was supported by an outside toxicology lab and a prestigious occupational medicine institute.
In relatively short order, we discovered that the material was not just toxic (as suspected}, but in fact so biologically
active that it was attracting interest from external physicians as a possible pharmaceutical because of its radical effect
on the circulatory system,
Executive management at our division could have attempted to brush off the preliminary test results as insufficient
and inadequate to justify withdrawal of the material from full-scale commercialization. They could have rationalized
away the risk and limited funding for what eventually became very expensive and sophisticated testing. Instead, they
fully supported our efforts and allowed the toxJcological testing and evaluation to proceed unhindered and in an unbi-
ased manner.
Ultimately, the division decided to withdraw the catalyst from all future commercial trials. As a result, no one was
ever seriously injured by the material.
If the toxicity of the catalyst had been fully understood in advance, the material might have been introduced suc-
cessfully into a highly controlled, specialized niche market where its unique properties could have been utilized fully
and safely. But the mainstream market was not equipped to handle the material. The division considered it too likely
that customers would use the substance as they did other, relatively safe commercial catalysts, without proper safe-
guards.
By RichardMacLean (MacLean, 2009).
18
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numerous variations that occur from batch to batch and product to product may lead to
unique toxicity characteristics for a given nanomaterial
2.2 Stakeholder Identification
Stakeholder participation is an integral element of sustainable decision making (Kiker et al.,
2005). Given the fact that the sustainability of a product may be viewed differently by different
stakeholder groups, it is important to obtain their input and value judgments in conducting a
sustainability assessment. In broad terms, a stakeholder includes any group or individual who can
affect or is affected by any aspect of a product (Freeman, 1984; Mitchell et al., 1997). These
stakeholders may include those that have a direct or indirect stake. For example, direct
stakeholders may include those with a vested financial interest in the company developing the
product or customers that will eventually use the product. Indirect stakeholders may include those
with the ability to influence the product development (e.g., regulators) (Young, 2008).
All groups or individuals that are likely to be affected, whether positively or negatively, by the
product throughout its life cycle should be listed through a brainstorming session. When listing
the stakeholders, it is often helpful to group them into different categories (e.g., workers,
management, customers, community, etc.). However, depending on where a product is in its
development cycle, the product uses, target market, and associated stakeholders may be difficult
to identify. Therefore, the list of stakeholders may expand and need to be updated and revised as
a product is further developed and commercialized.
Engaging all the identified stakeholders is often unrealistic and resource intensive. Accordingly,
decision-makers must narrow the list of stakeholders to those that seem the most appropriate to
engage for the assessment. To assist in this effort, stakeholders may be "mapped" based on their
level of interest, legitimacy, influence, or other factor relevant for the project (Bryson, 2004;
Young, 2008). Figure 2-2 includes an example stakeholder mapping approach.
High
Power
Low
Keep
Satisfied
Monitor
(Minimum
Effort)
Manage
Closely
Keep
Informed
Interest
Figure 2-2. Example of Stakeholder Mapping (Bryson, 2004; Young, 2008)
Stakeholders are typically engaged in the goal definition and scoping phase, evaluation and
interpretation of impacts and selection of final alternative approaches to mitigate impacts (steps 3,
5, and 8 of the framework). Participation strategies for soliciting stakeholder input may include
individual surveys, public meetings, workshops, interviews, or a combination thereof. The
appropriate participation strategy should match stakeholder preferences, which may be influenced
by the level of trust participants may have of each other, scientific and technical experts, and the
product developers. Furthermore, as the level of trust evolves, the participation strategies may
need to be adjusted as appropriate (Anex and Focht, 2002). In addition to the level of trust
between participants, the selected strategy may also reflect other factors such as the decision
context and available resources for the study (Kiker et al., 2005). Ultimately, the specific
involvement of individuals or groups will depend on how closely a particular issue is of interest
19
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and may affect them (Anex and Focht, 2002). For more discussion on the identification,
engagement, and analysis of stakeholder input, the reader is referred to Reed and coworkers
(Reed et al., 2009), Cuppen and coworkers (Cuppen et al., 2010), and Aaltonen and coworkers
(Aaltonen, 2011), all of which provide useful insight based on case studies.
Involving Stakeholders
As indicated in section 1.4, a key step in the decision framework is to identify and engage
stakeholders who can provide input in defining the goal and developing sustainability metrics,
evaluating and interpreting impacts and selecting alternative approaches to mitigate impacts.
This is especially important when working in a collaborative manner, such as in a private-
public partnership, or in an industry consortium. As mentioned previously, stakeholders
include any group or individual who can affect or is affected by any aspect of the nanoproduct
(Freeman, 1984; Mitchell; 1997), and may also include experts such as LCA practitioners,
risk assessors, economists, or public health experts, or other scientists that may offer
important advice in assessing impacts and selecting approaches for mitigating these impacts.
A diversity of perspectives should be used to inform the project goals and scope, identify the
functional unit and alternatives (if a comparative assessment is to be conducted), refine the
methodology, monitor its implementation, and facilitate use of the information generated by
the study to make product improvements and, if a comparative assessment is conducted, to
choose safer materials and processes. Involvement throughout the project helps to ensure that
stakeholders contribute to, understand and support the outcome, enhancing credibility and
promoting product improvements. Stakeholders are drawn from the entire supply chain and
all life-cycle stages of the product. In addition to the experts identified above, typical
stakeholders may include: chemical and product manufacturers and suppliers; product users
and retailers; waste and recycling companies, government agencies; academics; and non-
governmental organizations. Those developing new technologies in the area of study (that may
be analyzed as potentially safer alternatives) should be included in the stakeholder group.
Early in the study, researchers and product developers should identify, contact, and inform
potential stakeholders of the proposed project goal and scope, methodology, and potential
benefits, to gain the expertise needed to conduct the study and representation of the broadest-
possible points of view. Stakeholders can be identified via industry conferences, trade groups,
academic institutions, or industry contacts. When proposing a collaborative effort (either by
sending out an invitation to a group, or making individual contacts), it is important to point
out the mutual benefits and potential savings that will result from sharing the cost of the study,
and from making product improvements that result in the use of less energy and materials and
provide the competitive advantages associated with generating fewer environmental impacts.
When contacting potential stakeholders, it is also important to consider and explain how
confidential business information will be protected, and to make clear that confidential data
will not be made public.
KathyHart, EPA LCA Project Leader (Hart, 2009)
2.3 Goal and Scope Definition
The goal definition and scoping phase of a sustainability assessment should include information
on the focus of the study, including the research questions to be answered, system boundaries,
and functional unit (quantified reference flow) of the product system. The term functional unit is
most often associated with LCA because it can provide a basis for comparison across the life
20
-------
cycle stages of dissimilar products having the same use. For example, a study examining
antimicrobial foot treatment for diabetics might be based on the amount of product needed for
one treatment, such as a pair of socks containing nanoscale silver or the prescribed quantity of an
antimicrobial ointment dose. Other assessment tools may require a different reference such as the
mass of a product unit or its monetary value. These simpler reference flows are also applicable
for LCA when considering a single product or similar products (i.e. silver socks made by
different manufacturers). The key point to remember going forward is that once a reference flow
is established, it can easily be converted into equivalent forms to meet the needs of the various
assessment tools.
The overall goal of a sustainability assessment is to select and/or develop a product, process, or
service that is sustainable. To make this a more practical goal, the concept of sustainability should
be broken down into criteria for each pillar (environmental, economic, and social), paying special
attention to any criteria and indicators that are pertinent to the product in question. If the
manufacture of a nanoproduct is particularly energy-intensive, then impacts associated with
energy use might be particularly critical to the overall sustainability of the product. Energy-
related criteria and indicators could include, but are not limited to, air and water emissions from
upstream power plants, material resources used for energy production, electricity costs, power
plant working conditions, and the impact of power plants on local communities. However,
impacts not related to energy use (ozone depletion, acidification, material costs, etc.) must not be
excluded a priori because they may actually be the more severe impacts for the product based on
other phases of the life cycle. Ultimately, the product developers should work with the
stakeholders to select relevant criteria that accurately encompass sustainability (Azapagic et al.,
2006). Table 2-3 provides a list of example sustainability criteria for each pillar. Some criteria
such as noise may not fit uniquely with one pillar. In such cases, the criterion in question should
be assigned to a pillar during goal and scoping to avoid (if possible) double counting the impact.
The list provided is by no means authoritative with the understanding that ultimate placement of
criteria within the pillars may depend on the indicators and metrics needed to measure them and
what tools are available to assess these metrics and indicators.
Table 2-3. Examples of Sustainability Criteria (adapted from Azapagic et al., 2006)
Environmental
Energy use
Resource use (renewable and
non-renewable)
Emissions (air, water, land)
Global warming
Ozone depletion
Acidifications
Ecotoxicity impacts
Human toxicity impacts
Water eutrophication
Economic
Macro-economic
Environmental liabilities
Taxes
Micro-economic
Capital costs
Operating costs
Consumer costs
- Profitability
Social
Provisions of employment
Health and safety of:
Employees
Customers
- Public
Nuisance
Noise
- Odor
Public Acceptability
A list of complete sustainability criteria is too numerous to include here and would pose a
daunting challenge if stakeholders tried to account for the entire set. Therefore, stakeholders must
select relevant criteria from each pillar to adequately capture sustainability. The selection process
is not trivial based on the varying preferences of stakeholders with regard to sustainability. For
21
-------
insight, readers are encouraged to read the work of Hirschberg and coworkers (Hirschberg et al.,
2007) who have studied the selection process and offer guidance on what to consider when
building a criteria set to insure it is scientific, functional and pragmatic. For example, a
manageable number of criteria should be selected equally from the three pillars for balance while
capturing essential technological characteristics of products and process to allow differentiation
amongst them. With a defined selection process, stakeholder preference can be incorporated in a
way that minimizes the subjective nature of sustainability. To illustrate the concept of balance, a
sustainability assessment for a given product might examine energy and resource use, global
warming, toxicity impacts, profitability, environmental liabilities, health and safety, and public
acceptance. It is also possible that certain criteria can only be evaluated qualitatively, such as
social issues. These approaches are permissible provided such choices are clearly defined and
justified in the scope of the assessment. These decisions may be based on the resources available
for the study, data availability, or the product development stage (EPA, 2006).
Preferences in Sustainability Criteria: The Case of Antimicrobial Textiles
Consider the growing use of nanoscale silver in antimicrobial textiles. A group of
stakeholders for a product in this application might include the product manufacturer, textile
groups, government agencies overseeing environmental and public health, consumer advocate
groups, and residents of the communities surrounding the manufacturing site. For the
manufacturers, profitability is obviously the most important criterion. However, profitability is
directly related to both operating cost and public acceptance. The operating costs will depend
on energy and resource use, potential emissions and environmental liabilities, taxes, and
employee safety. These criteria are all easily quantifiable based on an understanding of the
manufacturing process and workplace risk. The other concern for profitability, public
acceptance, is not readily quantifiable and may be evaluated qualitatively based on an
understanding of the market for the intended product. This might involve simple yes/no
questions to determine if a large enough consumer base exists or more detailed analyses of
factors that could create a potential negative public perception. Government agencies will
care more about the impact on the public and environment. Criteria for these needs will
include climate change (global warming, ozone depletion, acidification) and toxicity impacts
to humans and ecosystems. Again, these are all quantifiable criteria. However, as opposed to
the manufacturer, who might only focus on its own operation, government agencies will want
to know about the impacts associated with the entire life cycle of the product. In a similar
manner, consumers groups and local residents will be concerned with the potential health
effects associated with product manufacture and use. For these criteria, a quantitative
measure of health effects will be needed to satisfy the needs of the stakeholders. This will not
be easy for most nanoproducts given the lack of available toxicity data for nanocomponents.
In addition, consumers will also consider product cost when making a decision. What benefit
will the product be to the consumer if it is unaffordable? Again, until the manufacturer can
fully quantify the costs associated with the product, how can they provide an associated
consumer cost? This example should illustrate the complex nature of decision making for
sustainability. Each stakeholder will not only have his/her own important criteria that must be
satisfied, but will have differing scopes and boundaries when beginning the assessment
process that must be reconciled. Ultimately, the rules for selection (Hirschberg 2007) and
data availability will be detrimental when prioritizing the criteria for assessment.
22
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It is critical to recognize that a product is sustainable only if it is sustainable with respect to each
of the three pillars. Accordingly, if one or two pillars are excluded due to practical constraints
(i.e. resources, data availability, etc.), the resulting study must be identified as a partial
sustainability assessment, and the interpretation of results must discuss the excluded pillar(s) and
any known potential impacts associated with the pillar(s). While practical considerations cannot
be ignored, a lack of data or resources cannot be confused with the absence of impacts. The level
at which the criteria will be measured must also be considered. For example, the product
developers and stakeholders may be interested in impacts at the product (micro) level, an
industrial sector (meso) level, or an economy-wide (macro) level (Zamagni et al., 2009). These
distinctions are chosen based on the perceived ability to impart change on connected systems
within each level. Thus, little change to space, market, and time is anticipated for perturbations at
the product level while changes at the economy-wide level will affect all systems. Generally, it is
advisable for emerging technologies to start analyses at the product level and expand to the
economy-wide level as the product is brought to market and additional information becomes
available (Zamagni et al., 2009). In the absence of accurate data, possible macro-level
considerations can be included during the initial assessment if desired using qualitative evaluation
of criteria. Such evaluations can lead to greater insight during interpretation of results.
When defining system boundaries, it is important to include every step that could affect the
overall interpretation or ability of the analysis to address the issues for which it is being
performed. The system boundaries not only refer to processes, but include the geographical and
temporal boundaries in which the nanoproduct will exist. These last two factors will help identify
suitable data quality criteria and provide a context to interpret results. In determining the system
boundaries, it is helpful to develop a system flow diagram, as shown in Figure 2-3, to depict the
activities and direction of flow of products and materials. This will also be useful later on in
guiding the efforts to gather data for assessment. Each system step should be represented
individually in the diagram, including the production steps for ancillary inputs or outputs such as
chemicals and packaging.
For a sustainability assessment, the functional unit has been defined as a basis to normalize data
using equivalent use (or service provided to consumers) to provide a reference for relating
impacts across life cycle stages as part of an improvement assessment. The functional unit is also
useful for comparing alternate product systems or technologies. However, as discussed
previously, any comparisons discussed in this framework are internal to a company's own
processes or alternatives. Given that nanotechnology is an emerging field, the eventual function
of the product and service level to the customer may not be known. As a result, it may not be
possible to develop a functional unit, especially if the product is still in development (Klopffer et
al., 2007). In such cases, the product developers should determine whether reasonable
assumptions may be made about the eventual product use and anticipated service provided to the
customer. If it is not possible to develop a service-based functional unit and the assessment does
not compare product systems, the product developers should determine another basis for
organizing the data and results into context.
23
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Fi*ld
Preparation
1^
Planting
|
i 1 i I
1 Irrigation Soil Wood Insecl
conservation uoniroi Manager
1
I
Harvesting
1
Seed Cotton Storage
I Ginning
1
Classing
iirzi
I Transportation
I
Marketing
1
[ Transportation
I
Yarn Production
TL,
1 Transportation |
|
Fabric Manufacturing
1
C
i
Ground
[^^r«p»alk>n^^
^
1 Silver Ore Extraetio
, i
i
mj Ben«ftc(aUon
1 Transportation
1
Silver Feedstock
manyfacturing
i
Transportation
i
Dislnbutioni
1
NanoscaJe Silver
Manuifaclurln§
Transportat ion
..,,,. 1
^==^r
Transportation j
1
Distribution |
1
Use
Wear and Wash)
1
Disposal
Figure 2-3. Sample Goal and Scope definition: The life cycle of a pair of cotton socks
containing antimicrobial silver.
24
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3. Assessing Environmental, Economic, and Social Impacts
The following section presents a summary of methods for assessing the environmental, economic,
and social impacts of a nanoproduct. These assessment methods largely reflect methods that are
commonly used by industry and LCA practitioners. They were selected because they can be
applied to holistically assess nanoproducts and are based on citable standards and guidance for
application. Qualitative as well as quantitative assessments may also be used, if needed. For
example, the EPA's Comprehensive Environmental Assessment (CEA) method is being
developed as a semi-quantitative tool based on expert judgment to identify information gaps and
research needs (EPA, 2010).
In most cases, it is not necessary (or practical) to apply all of the available methods (Zamagni et
al., 2009). The determination of which methods are most appropriate will depend on the
applicability of the technique, whether the method will respond to the research questions and
criteria, and the available resources for conducting the sustainability assessment. In addition,
given the uncertainty associated with nanoproducts, any tool selected should address uncertainty
and how it may affect the assessment given the nature of nanotechnology. The work by
Schepelmann et al. (CALCAS, 2008) may be a helpful resource to aid in selecting methods as it
provides an assessment of the strengths and weaknesses of various model and tools which support
sustainability analysis.
Given the nature of nanoproducts and nanomaterials and the fact that they are a new and
emerging technology, there are many issues and data gaps that may arise when assessing
environmental, economic, and social impacts. Although some issues are applicable for overall
aspects of a sustainability assessment, certain issues may be relevant for specific life cycle stages
and sustainability pillars. As described in Section 1.2, the key life cycle stages include:
1. Raw materials extraction,
2. Materials processing,
3. Product manufacture,
4. Product use, and
5. End-of-life disposition.
Some of the common issues and data gaps, and possible methods for addressing them, are
explained in detail below.
3.1 Environmental Assessment Methods
Many of the environmental protection strategies in which we have become accustomed can be
viewed as short-term or quasi-environmental fixes. We now understand that environmental
problems are rarely contained within a single resource area or within a single product's life cycle.
Instead, they require longer term strategies that extend across geographic regions and timeframes.
It has become obvious that a more integrated, systems-based approach is required to meet the
needs of today while maintaining the prospects for the same quality of life for tomorrow's
generation. As a result, many methods and tools are being offered to assess the environmental
impacts of a product throughout its life cycle (see Table 3-1). For more detailed information
about applying the methods, please consult the references listed on the right-hand side of the
table. As discussed in Section 2, the method or tool selected should be based on the goal and
scope of the sustainability assessment.
25
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Table 3-1. Key Environmental Assessment Methods
Method Description/ Scope/ Impacts Measured Reference
Benefits Stage
Life-Cycle
Assessment
(LCA)
Carbon
Footprint
Environmental
ly-Extended
Economic
Input-Output
(EEIO) Life
Cycle Analysis
Life Cycle Risk
Assessment
e.g., Nano Risk
Assessment
Evaluates potential
environmental impacts
associated with a
product, process, or
activity. LCAs consider
multi-media, multi-
attribute impacts by
quantifying energy and
materials used and
wastes released to the
environment from
cradle to grave.
Both GHG Life Cycle
Analysis and Carbon
Footprinting aim to
account for the release
of greenhouse gases
that contribute to global
climate change. The
principal gases are
carbon dioxide,
methane, nitrous oxide,
and fluorinated gases,
such as chlorinated
fluorocarbons (CFCs).
Assesses the economy-
wide environmental
impacts of a product
throughout its life cycle
stages. Note that this
method may also be
used to conduct an
economic assessment
(see Section 4).
Characterizes the
nature and magnitude
of health risks to
humans (e.g., residents,
workers, recreational
visitors) and ecological
receptors (e.g., birds,
Product
to
regional/nati
onal level
All life cycle
stages
All life cycle
stages
Product/
micro level
to economy-
wide level
All life cycle
stages
Product/local
and meso
level
All life cycle
stages
• Natural Resource
Use (e.g., water,
nonrenewables,
etc.)
• Global warming
• Ozone depletion
• Smog Formation
• Acidification
• Eutrophication
• Human Health
• Ecotoxicity
• Land Use
• Etc.
• Carbon
• Greenhouse gases
• Global warming
• Climate Change
• Economic activity
generated
• Natural Resource
Impacts (e.g.,
energy use, fuel
use, ores, etc.)
• Abiotic Ecosystem
impacts (e.g., green
house gas
emissions, ozone
depletion, smog,
etc.)
• Toxic releases by
sector and
chemical
• Health hazards
(e.g.,
neurotoxicity, skin
absorption,
genotoxicity, etc.)
• Environmental
(e.g., aquatic,
(Baumann and
Tillman, 2004;
EPA, 2006;
ISO, 2006;
SET AC, 1992)
(BSI, 2008;
WRI, 2010)
(CMU, 2008a;
Klopfferetal.,
2007; Wiedema,
2010)
(EPA, 2010;
Walsh and
Medley, 2007)
26
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Method Description/ Scope/ Impacts Measured Reference
Benefits Stage
Ecosystems
Services LCA
(ECO-LCA)
Sustainable
Materials
Management
fish, wildlife) from
chemical contaminants
and other stressors that
may be present in the
environment. Risk
assessments are
composed of two sub
assessments: an
exposure assessment
and a hazard
assessment.
Expands upon
traditional LCA and
quantifies ecosystem
services over the life
cycle of a product.
Quantifies the relative
magnitude of material
flows in the global
economy. Methods of
material flow
accounting, such as
Material Flow Analysis
(MFA) and Total
Material Requirements
(TMR), are used.
Product/
local, meso
All life cycle
stages
All life cycle
stages, with a
focus on
material
extraction
and end-of-
life
management
(recycling).
terrestrial, avian,
etc.)
• Safety (e.g.,
explosivity,
reactivity,
corrosivity, etc.)
Ecological services
(e.g., land-use).
Flows (Kg)
(Zhang etal.,
20 lOb; Zhang et
al., 2010c)
(Fiksel, 2006)
-------
Life Cycle Assessment
The most comprehensive method to assess the environmental impacts of a product, process, or
activity throughout its life cycle stages is environmental life cycle assessment (LCA). A LCA
accounts for the physical flows, i.e. the inputs and outputs, across the full life cycle of a product
system, from materials acquisition to manufacturing, use, and final disposition (see Figure 3-1).
As outlined in the International Standards Organization (ISO) 14040 series, an environmental
LCA study has four major components: goal definition and scoping, life cycle inventory (LCI),
life cycle impact assessment (LCIA), and interpretation of results (ISO, 2006).
Inventory data are subjected to life cycle impact assessment models, which seek to establish a
linkage between a system and the potential, related impacts. The impact models are often derived
and simplified versions of more sophisticated models within each of the various impact
categories.
Although work is ongoing to reach consensus on which impact categories to include, the
International Reference Life Cycle Data System (ILCD) Handbook (JRC, 2010) provides the
following list of commonly used categories:
• Ozone Depletion • Fossil Fuel Use
• Global Warming • Land Use
• Human Health • Water Use
• Ecotoxicity • Land Use
• Eutrophication • Resource Depletion
• Acidification
• Smog Formation
These simplified models are suitable for relative comparisons of the potential to cause human or
environmental damage, but are not indicators of absolute risk or actual damage to human health
or the environment. For that, a risk assessment is needed. In the case of a traditional risk
assessment, it is possible to conduct very detailed modeling of the predicted impacts of the
chemical on the population exposed and even to predict the probability of the population being
impacted by the emission. In the case of LCA, hundreds of chemical emissions (and resource
stressors) which are occurring at various locations are evaluated for their potential impacts in
multiple impact categories. The sheer number of stressors being evaluated, the variety of
locations, and the diversity of impact categories makes it impossible to conduct the assessment at
the same level of rigor as a traditional risk assessment. Instead, models are based on the accepted
models within each of the impact categories using assumptions and default values as necessary.
LCA is a well-established methodology for evaluating the environmental impact of products,
materials, and processes. By including the impacts throughout the product life cycle, LCA
provides a comprehensive view of a product's environmental aspects. It is also valuable in
evaluating the many interdependent processes that are involved in a product system. A change to
one part of this system may have unintended consequences elsewhere. LCA identifies the
potential transfer of environmental impacts from one medium to another (e.g., eliminating air
emissions by creating a wastewater effluent instead) and/or from one life cycle stage to another
(e.g., from use and reuse of the product to the raw material acquisition stage). If an LCA were not
performed, the transfer might not be recognized and properly included in the analysis because it is
outside of the typical scope or focus of product design and selection processes.
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A workshop comprised of international experts from the fields of both LCA and nanotechnology
concluded that the LCA ISO-framework (ISO 14040:2006) (ISO, 2006) is fully suitable to all
stages of the life cycle of nano-components and nanoproducts (Klopffer et al., 2007). However,
the workshop attendees acknowledged a number of operational issues that need to be addressed,
such as functional unit selection, inventory data collection and/or estimation, allocation, and
toxicity assessment. Similarly, Bauer and coworkers have also pointed out that a suitable
definition of the functional unit and system boundaries for nanoproducts will be necessary to
facilitate comparative assessments (Bauer et al., 2008). A complete list of LCA services,
software tools and databases can be found at http://lca.jrc.ec.europa.eu/lcainfohub/directory.vm.
F
»
roduct System Boundary
Raw Materials
Extraction
,
Inputs
if
Materials
Processing
(materials, energy, resources)
,
T
Product
Manufacture
,
V
Product Use
V )
,
T
End of Life
(EOL)
•9 ¥ f » V
[ Outputs (products, emissions, wastes) ]
Figure 3-1. General Framework for a Product Life-Cycle Assessment (LCA)
Carbon Footprint
Carbon Footprint (CF) has become widely used in relation to the threat of global climate change.
CF is the measurement of the overall amount of carbon dioxide (CO2) and other greenhouse gas
(GHG) emissions (e.g., methane, nitrous oxide, etc.) associated with a product, a person, an
organization or an event. For products, the boundaries include the supply-chain and sometimes
use and end-of-life recovery and disposal. For simplicity of reporting, it is often expressed in
terms of the amount of carbon dioxide (tons or kilograms), or CO2- equivalents.
Two well-known accounting tools for quantifying and managing GHG emissions are the
Greenhouse Gas Protocol (GHG Protocol) (WRI, 2010) and BSFs "Specification for the
assessment of the life cycle greenhouse gas emissions of goods and services" (BSI, 2008).
In 2006, the International Organization for Standardization (ISO) adopted the Corporate Standard
as the basis for its ISO 14064-1: Specification with Guidance at the Organization Level for
Quantification and Reporting of Greenhouse Gas Emissions and Removals.
Several CF calculator tools are available on-line (e.g., http://www.carbonfootprint.com/)
Despite its ubiquitous appearance there seems to be no clear definition of the term carbon
footprint. There is still much confusion as to what it actually means, what it measures, and what
unit is to be used. While commonly understood to refer to certain gaseous emissions that are
relevant to climate change and associated with human production or consumption activities, there
is no agreement on how to measure or quantify a carbon footprint. Questions remain regarding
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whether the carbon components should be weighted and normalized based on their potential
effect in the atmosphere. Other questions that need to be answered include the following:
• Should the carbon footprint include just carbon dioxide (CO2) emissions or other GHG
emissions as well, e.g., methane?
• Should it be restricted to carbon-based gases or can it include substances that do not have
a carbon atom in their molecule, e.g., N2O which is another powerful GHG?
• Should the carbon footprint be restricted to substances with a global warming potential at
all, since there are gaseous emissions that are carbon-based and relevant to the
environment and health, such as carbon monoxide (CO) which can convert into CO2
through chemical processes in the atmosphere?
• Should the measure include all sources of emissions, including those that do not stem
from fossil fuels, e.g., CO2 emissions from soils?
The Carbon Footprint approach is included in this guidance because of its widespread use in the
management of GHG gas emissions. While developing strategies for mitigating climate change is
indeed important, we must be mindful to not exclusively focus on one factor and discount other
equally important environmental aspects, such those listed under LCA. Decision makers are
encouraged to build upon the results of the carbon footprint approach toward a holistic
examination of environmental impacts in order to identify potential unintended trade-offs
between different environmental categories.
Environmentally-Extended Economic Input/Output LCA
In conducting an LCA, the creation of a life cycle inventory often follows a "process-based"
approach in which the resource inputs and the releases to the environment are reported for all the
processes within the life cycle system. Because finding such process data can be challenging (see
Section 3.1.1) methodology developers created an approach that uses national economic
input/output (I/O) models to help estimate the materials and energy resources required for, and
the environmental emissions resulting from, activities in the entire economy (CMU, 2008b).
The process-based and the environmentally extended economic I/O based approaches have
advantages and disadvantages, and it is possible to create hybrid models that incorporate aspects
of both. As the name suggests, process-based LCAs model processes, such as the steps for
manufacturing carbon nanotubes. Although process-based LCAs can provide detailed information
about a nanoproduct system, they may necessitate artificial boundaries between the products of
interest and the rest of the economy.
The disadvantage of input-output-databases is that processes are aggregated at the level of
product groups rather than individual products. This disadvantage can be overcome by
conducting a hybrid analysis, which essentially links the inputs and outputs of a process-based
LCA into an input/output-database (Wiedema, 2010). For example, one could use process-based
LCA techniques to model the impacts of the production processes at a given facility, but use EIO-
LCA to model the supply chain impacts of the electricity purchased by the facility (CMU, 2008a).
Three main ways of combining process-based LCA and I/O- based LCA are: tiered hybrid
analysis, lO-based hybrid analysis and integrated hybrid analysis (CALCAS, 2008).
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Several I/O databases are available, including a free database from Open IO that covers the USA
in 430 industrial sectors, including emissions relevant to global warming. Open IO is jointly
administered by the Sustainability Consortium and the University of Arkansas Sam M. Walton
School of Business.
A well-known LCA-based approach that uses the economic input/output model was developed by
the Carnegie Mellon Green Design Institute and is freely available on-line (www.eiolca.net).
Life Cycle Risk Assessment
Life Cycle Risk Assessment (LCRA) integrates the traditional risk assessment paradigm
with a life cycle perspective. It attempts to examine potential human health and
ecological impacts (both positive and negative) in a broad, systematic manner by
stepping the decision maker through the life cycle of a material in identifying the
pertinent exposure pathways and forms of a substance. This, in turn, can identify the need
for more detailed evaluation at particular life cycle stages to characterize impacts
(Shatkin, 2008). The life cycle nature of the approach indicates that it encompasses a
cradle-to-grave framework while accounting for multi-media environmental fate and
transport, exposure, and effects on both ecological receptors and human health. Other
dimensions such as economic, political, security or societal factors are typically excluded.
In 2005, ED and DuPont entered into a partnership to develop a framework for the responsible
development, production, use, and end-of-life disposal or recycling of engineered nanoscale
materials, that is, across a product's life cycle. The resulting "Nano Risk Framework" (Figure 3-
2) develops profiles of nanomaterials' properties, inherent hazards, and associated exposures
throughout the material's life cycle (ED-DuPont, 2007).
Iterate
Describe
Material
&
Application
._
-~*==^-
Profile
Lifecycle(s
Properties
Hazards
Exposure
!
)
Evaluate Assess
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Document
& Act
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1
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&
Adapt
— —
_^-~-~
Figure 3-2. Nano Risk Framework (ED-DuPont 2007)
The ED-DuPont Nano-Risk Framework is not intended to be a full-scale life cycle analysis, in
which one pays prominent attention to resource inputs. Instead, it is intended to help users
assess, manage, and report the potential environmental, health, and safety risks associated
with a particular material and application. It follows a traditional risk-assessment paradigm
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similar to the one used by the U.S. Environmental Protection Agency (EPA) for evaluating new
chemicals (EPA's New Chemicals Program: http://www.epa.gov/oppt/newchems/index.htm).
However, it does not present a "one size fits all" approach. Different organizations, depending
their size and structure, will have differing ways of implementing the framework for maximum
effectiveness.
Ecosystems Services LCA
Natural ecosystems provide us with a multitude of resources and processes from clean drinking
water, to processes such as the decomposition of wastes, and other benefits such as pleasant
aesthetics. Ecosystems and the valuable services they provide (e.g., soil, pollination, flood
prevention and cropland) are often overlooked, but recently attempts are being made to include
these aspects in environmental assessment tools. For example, the Ohio State University Center
for Resilience developed a free, online tool called Eco-LCA (http://resilience.eng.ohio-
state.edu/ecolca-cv/). Eco-LCA was developed to complement other LCA tools by showing how
different products and materials have different impacts on nature.
Those services are divided into four areas: supporting services (soil, pollination, sunlight,
hydropotential, geothermal, wind), regulating services (flood protection, disease regulation,
carbon sequestration), provisioning services (fuels, ores, water, timber, cropland), and cultural
services (spiritual and recreational benefits). Eco-LCA includes various aggregation schemes that
are based on thermodynamic concepts (Zhang et al., 2010a).
Sustainable Materials Management
Sustainable Materials Management (SMM) is an approach to promoting sustainable materials use,
integrating actions targeted at reducing negative environmental impacts and preserving natural
capital throughout the life cycle of materials by taking into account economic efficiency and
social equity (OECD, 2005). At this point, SMM is more a concept than a single methodology.
Many suggest that the focus of SMM should be on environmental impacts of the materials flows,
rather than simply on volumes or weights of materials alone (OECD, 2005). Material Flow
Analysis, or Accounting, (MFA) is a complementary tool that tracks the amounts of a material as
it goes into multiple products, as they enter and exit the economy through various types of
transactions. Although there is no global consensus on MFA methodology, MFA can provide
important background information and data for life cycle approaches and SMM.
SSM is especially applicable to nanotechnology because non-renewable metals and rare earths are
often used to manufacture various nanocomponents. Although the application of nanotechnology
could lead to significant reductions in the consumption of critical minerals compared to
traditional technologies, the need to extract more metals, such as silver, gold, titanium and
lithium, and other exotic rare earth metals, such as europium, cerium, neodymium, gadolinium,
and terbium, will continue as the demand for nanoproducts grows. These natural resources are in
limited quantities and there may not be enough supply of them in the near future.
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The Need for Multiple Methods to Understand the Complexity of Nanotechnologies
The primary impacts associated with the development of Carbon nanotube (CNT) nanoproducts
can be attributed to either the manufacture of CNTs and CNT nanoproducts or the release of
CNTs into the environment throughout the life cycle. Manufacturing impacts are related to both
the selection of raw materials, particularly the metal catalysts and carbon precursors, and the unit
operations involved during the incorporation of CNTs into nanoproducts. For example, the
popular chemical vapor deposition (CVD) process used to generate CNTs involves thermal
pretreatment of the gaseous hydrocarbon to increase the feedstock purity (Journet et al., 1997;
Sinha et al., 2006) and accelerate formation and growth of CNTs (Plata et al., 2009). Although
beneficial to the process, this step can be responsible for the airborne release of greenhouse gases
(GHGs), volatile organic compounds (VOCs), and polycyclic aromatic hydrocarbons (PAHs)
(Plata et al., 2009). Likewise, the formation and release of carbon soot as a byproduct upon
heating the precursor during arc discharge processes is possible (Plata et al., 2009). Photo-
reactive VOCs can cause additional impacts like smog formation and ozone depletion (Plata et
al., 2009; Singh et al., 2008; USEPA, 1976). Certain PAHs can accumulate and persist in the
environment, posing a threat to human health as a cancer risk (Plata et al., 2009). Carbon soot
formation not only disrupts the radiative heat balance (Kauffman and Fraser, 1997) of the
atmosphere but is a serious concern for public health (USEPA, 1977). Furthermore, Plata et al.
(2009) observed a significant increase in the quantity of greenhouse gases emitted during CVD
when the reactor temperature is only slightly increased. Similarly, the thermal pretreatment of
ethane as a carbon precursor results in the formation of larger quantities of byproducts including
GHGs such as methane, several photo-reactive VOCs, and toxic compounds such as benzene and
1,3 butadiene (> 36000 ppmv) (Plata et al., 2009). The acid purification step used to remove trace
impurities of the metal catalyst from raw CNTs may result in the discharge of unconventional
liquid waste to wastewater treatment plants (Singh et al., 2008). Some of the waste compounds
such as molybdenum or cobalt chloride (MoCl2, CoCl2) are not completely treated by wastewater
treatment plants and can pose serious risks to aquatic species if released into fresh-water bodies.
Molybdenum compounds are known to cause anoxic conditions (Arnold et al., 2004; Gooday et
al., 2009) while cobalt compounds support the growth of blue-green algae (harmful algal blooms)
which can lead to eutrophication (Hansen et al., 1954).
The potential health risk of CNT nanoproducts is a function of their release probability and the
inherent toxicity of the CNTs. The potential release of aerosolized CNTs at CNT and
nanoproduct manufacturing sites greatly depends on the type of process and work place practices
adapted to handle free CNTs (Kohler et al., 2008). The aerosolization of CNTs is a function of
their size and rates of diffusion, agglomeration, deposition and re-suspension into the surrounding
environment (Kohler et al., 2008). For example, the HIPCO method of CNT synthesis releases
larger amounts of CNT aerosols than other synthesis methods. Similarly, gas phase product
recovery of CNTs and unit operations such as mechanical milling and dry CNT powder mixing
increase the probability of forming CNT aerosols (Kohler et al., 2008).
The probability of CNT release from nanoproducts during use and disposal will depend on the
durability of the nanoproduct. For example, a window frame or automotive body panel made with
a CNT-polymer composite material is expected to have a minimal chance of CNT release during
use. On the other hand, products such as CNT textiles and CNT coatings may exhibit a larger
potential for release, particularly when subjected to thermal degradation, photochemical oxidation
and other harsh weathering patterns (Kohler et al., 2008). Furthermore, there are concerns that
CNT-bearing waste will cause problems during conventional disposal processes. Incineration of
CNT-laden waste may generate CNT aerosols if the operating temperature of the incinerator
facility is less than the decomposition temperature of CNTs (Kohler et al., 2008). The presence of
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CNTs in landfill leachate may affect the remediation efficiencies for other hazardous pollutants
(e.g. PAH and Pyrene) by altering their fate and bioavailability in the environment (Petersen et
al., 2009; Yang etal., 2006).
The release of CNTs is important because it is the first step in exposure to humans and biological
receptors. Once CNTs are released into the environment, impact of exposure will depend on the
toxicity of CNTs as determined by their physico-chemical properties. The extent of toxic damage
will be influenced by both the bioavailability (uptake) and bioaccumulation of CNTs by
biological receptors (Linkov et al., 2009). Bioavailability and bioaccumulation potentials are
dependent on many factors including the quantity of CNTs released, the physical properties of
CNTs (i.e. size and shape), surface functionality, dispersivity, the presence of impurities (Kushnir
and Sanden, 2008; Linkov et al., 2009), and the environmental media for exposure (air, water or
soil). Ultimately, the toxicity potential of CNTs is not only varied based on the physical
properties of CNTs, but also based on the physico-chemical properties of the surrounding
environment and biological nature of cells that are exposed to the CNTs.
If LCA is used exclusively to assess the environmental impacts of a CNT nanoproduct, it will
adequately capture the issues related to resource management and climate change issues such as
acidification and eutrophication. Shortcomings will arise from the models underlying the
characterization of impacts to human and ecosystem health because they have not been proven
with regard to their ability to account for the many factors discussed above that dictate the toxic
risk of CNTs. These models have been developed using average environmental factors and lack
site-specificity to account for the influence of the factors on the behavior of CNTs. Even the
traditional risk assessment approach, which is based on dose-response studies, may not account
for the cumulative risk of a CNT nanoproduct because it is typically a mass-based assessment and
neglects the influence of chemical properties. However, it does provide the opportunity to better
address the influence of local environmental factors. Thus, the incorporation of a modified risk-
based health impact model accounting for chemical factors under site-specific conditions into the
LCA framework would achieve a maximum understanding of the impacts of a CNT nanoproduct
to guide decisions at the local level.
3.1.1
The accuracy of assessment results obtained using the various methods listed in Table 3-1 will
depend greatly on both the quantity and quality of data used to perform them. Although the
required data sets vary from method to method, they generally fall into two categories, life cycle
processes or chemical risk. Understanding where to obtain this information can greatly expedite
the assessment process.
Detailed process flow data forms the basis for numerous techniques, including LCA, CF, EIO-
LCA, Eco-LCA, and SMM. The best sources of data for these assessments are actual
manufacturers and waste handlers. However, collection of data from primary sources can be time
consuming. In the absence of this data, preliminary Life Cycle Inventories (LCIs) can be built
using any of the following sources: existing LCI databases (e.g., U.S. LCI Database, Ecoinvent,
Gabi, etc.), journal articles, patents, government reports, and manufacturers' websites. This data
will be directly applicable for LCA, CF, and SMM. EIO-LCA simplifies data collection
somewhat because LCI data can be taken directly from pre-existing databases built on the U.S.
input-output tables. However, the most current version of this data represents 2002 and may not
accurately capture nanomanufacturing processes. Eco-LCA requires thermodynamic conversion
factors to express process data in a comparable form. The values should be available in
engineering and physical chemistry reference books or scientific journals.
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Chemical risk data is primarily used for LCRA, but is also necessary to some extent when
calculating characterization factors for the human health and ecotoxicity impact categories
tabulated in most LCA methodologies. LCRA data types include exposure factors, chemical
toxicity, and transport model parameters. These data must be established through rigorous
experimentation and require knowledge of site-specific environmental conditions. Pollutant
release data can be obtained from government reports and databases (e.g., EPA's Toxic Release
Inventory (TRI)). Toxicity, exposure, and transport data can typically be found in scientific
journals. For existing chemicals other than nanocomponents, LCA characterization factors might
already be available with suitable models such as USEtox (Rosenbaum et al., 2008). For
nanocomponents, these factors must also be derived experimentally and may be found in
scientific literature.
3.1.2 Issues Related to Environmental Assessment Methods
Limited life cycle inventory data. A critical issue with the assessment of any nanoproduct is the
limited availability of inventory data throughout the life cycle of the product. Products still under
development may have limited LCI data for the manufacturing stage. LCI data for this phase may
also become outdated as the product and manufacturing technologies evolve (Klopffer et al.,
2007). Because many nanoproducts are only beginning to enter the market, LCI data may
especially be limited for the use and end-of-life (EOL) stages. Furthermore, LCI databases (e.g.,
those available through Simapro and GaBi) are currently limited in scope and may not include
appropriate secondary data for nanotechnologies, such as material inputs, natural resource inputs,
and emission outputs (Khanna et al., 2007).
Based on the available data, a determination should be made as to whether it is possible to include
all stages of a product life cycle, discussed in further detail below. Developing a flow diagram of
the product system, such as that in Figure 2-3, can aid the data collection process. Such a flow
diagram can help identify the data sources for each category and assist in making reasonable
assumptions when reconciling missing LCI data. These assumptions should be consistent with
those developed as part of the goal and scoping phase. In addition, the input and output data that
are most likely to change as the nanotechnology or manufacturing process evolves should be
identified. For example, there may be a decrease in energy required to manufacture on a per unit
basis as production is scaled up. For existing technologies, data may already exist. However, for
emerging technologies, it may be necessary to gather data from laboratory experiments, models,
databases, or other studies.
Dynamic research environment. Since many nanoproducts are either in prototype development
or pre-production stage, they are constantly subjected to research improvements. Accordingly, the
LCI data with respect to a particular nanoproduct may lose reliability quickly because the
nanoproducts may undergo a series of improvement iterations within a short period of time. For
instance, Bauer et al. (Bauer et al., 2008), conducted an LCA (hypothetical study) on 15 inch
carbon nanotube field emission display CNT-FED devices. In 2007 when the study was
conducted, it was initially believed that the deposition of CNTs using chemical vapor deposition
(CVD) presented the most attractive solution for fabricating the cathode substrate. However,
further investigation indicated that the high temperatures of CVD did not allow use of glass
substrates in place of silica, meaning the CNT patterning could not be done using CVD (Fink and
Lee, 2005). Consequently, CNT cathode substrates are built using CNT pastes (Chu et al., 2006)
or inks (Kordas et al., 2006). Since the process of manufacturing CNT-FED changed
significantly, the LCA study conducted by Bauer et al. (Bauer et al., 2008) using CVD grown
CNT cathode substrates lost its significance within three years.
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Access to confidential business information (CBI) and proprietary data. LCI data may also be
limited by concerns over confidential business information (CBI) and other proprietary data from
firms upstream and downstream of the product developer. If this data is pivotal to an analysis, it
may be more effective for a third-party or consultant to work with the companies in conducting
the assessment. This way, the third-party could sign non-disclosure agreements to aggregate and
protect any confidential data from the manufacturers. In addition, the extent to which upstream
and downstream companies could provide aggregated data to the product developers that does not
disclose confidential information should also be explored. Although this would generate
additional uncertainty, it would provide a starting point for generating LCI data from all the life
cycle stages. As noted above, LCI databases may also provide inventory data on upstream
processes.
Anticipating the Challenges of Collecting LCI Data
One of the hardest parts of conducting an LCA is obtaining the necessary data because
the most accurate data often requires direct knowledge of industrial products and
processes. Unfortunately, this data is typically considered a "trade secret" by industrial
sources and is not readily available. So how does one reach out to companies and
persuade them to look beyond their initial fears and contribute their knowledge to a life
cycle inventory (LCI)? I was forced to ask myself this same question when I decided to
perform an LCA of a popular nanoproduct. The following is a summary of what I learned
by going through the process.
The current climate of the nanotechnology industry is extremely cut-throat as
nanomanufacturers seek to establish themselves as major players in the nanocomponent
market. Their livelihood is dependent upon protecting their manufacturing processes
because these processes are what define the company. In order to get companies to open
up about their process, you as an LCA practitioner must first gain their trust. This can be
a difficult process, but one that ultimately begins with the mindset of the practitioner.
Instead of viewing companies as mere sources for data, I tried to see the LCA process
from their perspective and identify potential outcomes of my work that could benefit their
day-to-day business operations (i.e. process optimization, waste reduction, etc.). I
familiarized myself with their goals and achievements to better justify how my project fit
with their business strategy (i. e. environmental stewardship, community interaction, etc.).
This allowed me to put together a unique "sales pitch " for each company that invited
them to be an active part of an exciting project and not just one of a dozen data sources
for a technology assessment. In addition, I avoided solicitation through random contact
and meticulously identified a member of senior management that would best serve as a
point of contact (i.e. vice president of manufacturing, plant manager, etc.). As a final step
in building trust, I offered to protect their data through agreements of non-disclosure.
While not every company I contacted was willing to help, these efforts over time did allow
me to identify enough sources to complete the LCI for my project.
D. E. Meyer
EPA National Risk Management Research
Laboratory, Cincinnati, Ohio
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Uncertainty regarding service level to the customer. The eventual function of the
nanotechnology and service level to the customer may not be known, which may limit the ability
to develop an appropriate functional unit. As discussed in Section 2.3, reasonable assumptions
may need to be made about the eventual product use and anticipated service provided to the
customer to develop an appropriate functional unit. If it is not possible to develop a service-based
functional unit and different product alternatives are not compared, then another basis for
organizing the data and for putting results into context should be determined (e.g., amount of
principle inputs and outputs).
Development of new decision rules. Decision rules commonly used for other technologies may
not be suitable for nanotechnologies. Typically a mass-based cut-off is used to determine which
materials to include in the product system. However, given the small scale and mass of
nanomaterials, this may not be appropriate. Therefore, decision rules should also include
materials that are of known or suspected environmental and energy significance regardless of
size.
Uncertainty regarding upstream resource use. Nanoproducts are frequently high-tech devices
that require rare metals for production. If there is reason to believe that scarcity will drive up
material costs, this factor should be included in the sensitivity analysis. If the uncertainty is too
great or is unknown, then a qualitative discussion of the potential impacts should be included.
Removing a resource from a region also impacts resource availability for local inhabitants and
typically is further exacerbated by low initial reserves. In such cases, both the impact of mining
operations on the effected population, as well as any impacts caused by the loss of the extracted
materials should be considered.
Limited toxicity data. There is very limited quantifiable data on the toxicity of nanotechnologies
to human health and the environment (Khanna et al., 2007; Klopffer et al., 2007). There are
several options to consider when addressing this issue. Toxicity data may be gathered from
laboratory experiments, models, databases, or other studies (Walsh and Medley, 2007). For
example, a study by Sengul (Sengul et al., 2008) provides a comprehensive review of
technologies used to manufacture nanomaterials and associated environmental impacts.
Currently, the Organisation for Economic Co-operation and Development (OECD) is testing a
representative set of manufactured nanomaterials for human health and environmental effects,
including:
• Fullerenes (C60), • Cerium oxide,
• Single-walled carbon nanotubes (SWCNTs), • Zinc oxide,
• Multi-walled carbon nanotubes (MWCNTs), • Silicon dioxide,Dendrimers,
• Silver nanoparticles, • Nanoclays , and
• Iron nanoparticles, • Gold nanoparticles
. Titanium dioxide, (OECD, 2008)
• Aluminium oxide,
When considering data from toxicity studies, it is important to ensure data relevance and accuracy
through the review of important qualifiers, key assumptions, and material properties (Bell, 2007).
In addition, when extrapolating data from laboratory experiments, it is important to consider the
limitations of the studies and whether they may be reasonably extrapolated (e.g., studies
extrapolated from animals to humans) (Bell, 2007). Depending on the available data, it may also
be appropriate to conduct a threshold analysis to determine the toxicity level at which the
nanomaterial becomes a significant contributor to the overall impacts (Klopffer et al., 2007).
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Similarly, a scenario-based assessment or worst-case scenario assessment may be conducted, in
which the impact potential of the nanomaterials is assumed to be as high as that of the most toxic
materials (Klopffer et al., 2007). If data are not available, a qualitative assessment based on
physical and chemical properties that may influence toxicity may be conducted. For example, as
discussed in Section 2.1, changes in the size and shape of a nanomaterial may influence
deposition patterns in the human respiratory tract. Excluding human health and/or ecotoxicity
impacts (e.g., aquatic ecotoxicity, human health cancer) as part of the assessment and only
focusing on environmental impacts (e.g., energy use, global warming, ozone depletion) until
additional data become available is also an option (Klopffer et al., 2007), although this exclusion
should be clearly identified in the final report.
Limited exposure data. Given uncertainty regarding the nature and extent of future commercial
use of the nanoproducts, there is limited exposure data with which to conduct risk assessments
(Ostertag and Husing, 2008; Walsh and Medley, 2007). Although toxicity is an important element
of risk assessment, it is only half of the analysis; the analysis of risk requires information about
both toxicity and exposure (Wiesner, 2006). Many studies have assessed different exposure
pathways relevant to nanomaterials throughout the life cycle stages (EPA-SPC, 2007). As noted
previously, if nanomaterials are embedded as part of larger objects (e.g., nanocomposites and
nanocrystalline solids), they are less dispersive and present lower risk than if they are used as free
nanoparticles, nanorods or nanofibers (Ostertag and Husing, 2008). Tools for exposure
assessment include monitoring, sampling, and modeling. However, these approaches have
limitations due to the unique characteristics of nanomaterials (EPA-SPC, 2007). For example,
unlike typical exposure assessment, mass may not be the appropriate metric by which to
characterize exposure. Instead, surface area may offer a better measure for assessing exposures
(EPA-SPC, 2007).
Given these limitations, conducting an initial "screening level" exposure assessment to identify
gaps and "priority starting points" for a thorough exposure assessment as data becomes available
should be considered (Ostertag and Husing, 2008) . As part of this approach four key steps should
be followed, including (1) defining system boundaries, (2) identifying relevant product parts,
flows, stocks, processes and emissions throughout the life cycle, (3) characterizing the potential
of generation, emission, and exposure for the areas identified in step 2, and (4) identifying
priority points for the exposure assessment (Ostertag and Husing, 2008). To identify potential
emission sources, relevant literature sources that have studied likely areas of exposure to
nanoparticles throughout the life cycle should be reviewed (EPA-SPC, 2007; Park, 2009; Sengul
etal., 2008).
In addition, a scenario-based or worst-case scenario assessment may be conducted (Klopffer et
al., 2007). For example, one study that modeled the exposure of different nanoparticles in the
environment looked at a "realistic-exposure scenario" and a "worse-case exposure scenario" to
develop a range of concentrations of the nanomaterials in the environment (Mueller and Nowack,
2008).
3.1.3 Challenges in Conducting Environmental Assessments
Like any other new technology under development, early application of nanotechnology is
surrounded by uncertainties about the potential effects on environmental and human health and
safety. Based on the current state of knowledge, the risk is real for some nanotechnologies, but as
yet unquantifiable. Current information regarding the environmental effects and health risks
associated with nanomaterials is limited and assessing their associated risk is not a
straightforward process. Advances are needed to advance nanoproduct risk assessment and risk
management. Meanwhile, efforts should be directed toward a better understanding of tradeoffs
38
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and finding superior risk management alternatives instead of setting a goal of estimating exact
risks and benefits.
Nanoproducts have many potential benefits to society with their development and deployment in
science, engineering and technology. Their benefits, however, need to be weighed against
potential impacts to environmental and public health. Adequate risk assessment processes are
needed to study these potential impacts, however, manufacturers need to realize that
environmental assessments should not be limited to risk of exposure to nano-components. In
addition, manufacturers need to understand how the manufacture, use, and waste management of
the nanoproducts they make could potentially contribute to ongoing environmental problems
during their life cycle from cradle to grave, including recycling. For example, is there the
potential for nanomaterials to impact global warming, stratospheric ozone depletion, acidification
(formation of acid rain) or eutrophication (the increase of chemical nutrients in water)?
LCA is a powerful tool for making holistic comparisons among possible or competing systems.
At the same time, not many studies on LCA of nanotechnology have been conducted; therefore
much of the needed information has to be extrapolated through experiences in other similar
industries. Furthermore, the rapid development of nanotechnologies and limited availability of
data makes full LCAs difficult to complete but easy to become outdated.
A two-day workshop on LCA of nanotechnological products (Klopffer et al., 2007) concluded
that the current ISO-standard on LCA (14040) (ISO, 2006) applies to nanotechnological products
but also that some development is necessary. The following main issues were identified:
There is no generic LCA of nanomaterials, just as there is no generic LCA of chemicals.
The ISO-framework for LCA (ISO 14040:2006) is fully suitable to nanomaterials and
nanoproducts, even if data regarding the elementary flows and impacts might be
uncertain and scarce. Since environmental impacts of nanoproducts can occur in any life
cycle stage, all stages of the life cycle of nanoproducts should be assessed in an LCA
study.
While the ISO 14040 (ISO, 2006) framework is appropriate, a number of operational
issues need to be addressed in more detail in the case of nanomaterials and nanoproducts.
The main problem with LCA of nanomaterials and nanoproducts is the lack of data and
understanding in certain areas.
While LCA brings major benefits and useful information, there are certain limits to its
application and use, in particular with respect to the assessment of toxicity impacts and of
large-scale impacts.
Within future research, major efforts are needed to fully assess potential risks and
environmental impacts of nanoproducts and materials (not just those related to LCA).
There is a need for protocols and practical methodologies for toxicology studies, fate and
transport studies and scaling approaches.
International cooperation between Europe and the United States, together with other
partners, is needed in order to address these concerns.
Further research is needed to gather missing relevant data and to develop user-friendly
eco-design screening tools, especially ones suitable for use by small and medium sized
enterprises.
Uncovering and recognizing environmental costs associated with a product, process, system, or
facility is important for good management decisions. Attaining such goals as reducing
39
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environmental expenses, increasing revenues, and improving environmental performance requires
paying attention to current, future, and potential environmental costs. How a company defines an
environmental cost depends on how it intends to use the information (e.g., cost allocation, capital
budgeting, process/product design, other management decisions) and the scale and scope of the
exercise. Moreover, it may not always be clear whether a cost or a saving, such as adopting an
energy efficient process, is classified as partly environmental and partly not. Whether or not a
cost is "environmental" is not critical; the goal is to ensure that relevant costs receive appropriate
attention (White et al., 1995).
Scale. Depending on corporate needs, interests, goals, and resources, environmental accounting
can be applied at different scales which include the following:
• Individual process or group of processes (e.g., production lines)
• System (e.g., lighting, wastewater treatment, packaging)
• Product or product line
• Facility, department, or all facilities at a single location - regional/geographical groups of
departments or facilities
• Corporate division, affiliate, or the entire company.
Scope. Whatever the scale, there is also an issue of scope. Scope refers to the types of costs that
are included. An initial scope question is whether the economic assessment extends beyond
conventional, internal costs to include potentially hidden, future, contingent, and often intangible
costs, such as image/relationship costs. Another scope issue is whether a company intends to
consider only those costs that directly affect their bottom line financial profit or loss, or whether
they want to also recognize the costs that results from their activities but for which they are not
directly accountable. These are referred to as external costs.
Environmental accounting terminology uses terms such as full, total, true and life cycle in order
to emphasize the fact that conventional approaches may be incomplete in that they overlook
important environmental costs (and potential savings). In looking for and uncovering relevant
environmental costs, decision makers may want to apply one or more tools. As the scope
becomes more expansive, firms may find it more difficult to assess and measure certain
environmental costs.
Conventional
Costs
Hidden
Costs
Contingent
Costs
Relationship/
Image Costs
Societal
Costs
Easier to measure
More Difficult to Measure
Figure 3-2. The Spectrum of Environmental Costs (White et al., 1995)
40
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The discussion in this section concentrates on conventional costs (raw materials, utilities, capital
goods, supplies, etc.) as well as environmental costs that are potentially overlooked in decision
making (see Figure 3-2.) This is where companies that are starting to manufacture products in an
environmentally sustainable way typically begin.
Examples of Environmental Costs Incurred by Companies
Potentially Hidden Costs
Regulatory
Notification
Reporting
Monitoring/testing
Studies/modeling
Remediation
Recordkeeptng
Plans
Upfront
Site studies
Site preparation
Permitting
R&D
Engineering and
procurement
Installation
Training _ . , .
, conventional costs
Inspections
Manifesting
Labeling
Preparedness
Protective equipment
Medical surveillance
Environmental
insurance
Financial assurance
Pollution control
Spill response
Stormwater
management
Waste management
Taxes/fees
Capital equipment
Materials
Labor
Supplies
Utilities
Structures
Salvage value
Bach-End
Closure/
decommissioning
Disposal of inventory
Post-closure care
Site survey
Voluntary
(Beyond Compliance)
Community relations/
outreach
Monitoring/testing
Training
Audits
Qualifying suppliers
Reports (e.g.. annual
environmental reports)
insurance
Planning
Feasibility studies
Remediation
Recycling
Environmental studies
R&D
Habitat and wetland
protection
Landscaping
Other environmental
projects
Financial support to
environmental groups
and/or researchers
Coiningem COSES
Future compliance costs
Penalties/fines
Response to future
releases
linage
Corporate image
Relationship with
customers
Relationships with
investors
Relationship with insurers
Remediation
Property damage
Personal injury
damage
Lega! expenses
Natural resource
damages
Economic loss
damages
and Relationship Costs
Relaiiorsnp witn
professiora staff
Relatiorsnp witn
workers
Relatiorsnp witn
suppliers
Relationship with
lenders
Relationship with
host communities
Relationship with
regulators
(EPA 1995)
Life cycle costing (LCC) can be viewed as building on the ISO standards of LCA as a method for
calculating costs throughout the life cycle of a product. LCC is based on the same physical
product system used in LCA, and summarizes all costs associated with a product from inception,
to development, use, and disposition (see Figure 3-3). However, it is pertinent to know the life
cycle costs from different perspectives, and so costs are typically separated into two segments:
41
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those paid by manufacturers and those paid by consumers or society (SETAC, 2009). There are
three types of cost categories to consider when conducting an LCC:
1. Internal costs are those that are associated with real monetary flows. For example, it
may include costs associated with raw material purchase, transportation, production, or
incineration. Note that "internal costs" refers to costs that are directly covered by any
stakeholder in the product system, including producers, consumers, end-of-life recyclers
and landfill managers, and any other stakeholders involved in the product system. All
internal costs should be included in a LCC.
2. Anticipated internal costs are costs that do not yet exist, but are anticipated in the future
(e.g., future disposal costs from anticipated regulations). Depending on the study's goal,
anticipated internal costs may be included in a LCC.
3. External costs are costs outside of the product system boundary, such as roadways for
facility construction or maintenance of a port. These costs should not be included in a
LCC.
Resources
Externa
Product
Boundary
Costs
+ 1
| Raw
>• Materials
1 Extraction
I
Revenue
y
Extern;
lities Extern
Costs
1 '
alities Exterr
Costs
r 1 <
alities Exterr
Costs
r i i
alities Exterr
Costs
r i <
C°steJ Materials | C°steJ Product | C°steJ Product | C°StSJ End of Lif
* Processing * Manufacture * Use * tnd-ot-Lit
Revenue^ JRevenue^ JRevenue^ J Revenue
\
Revenue
'
a lities Exterr
I
Revenue
' i
alities Exterr
I
Revenue
p i
alities Exterr
I
Revenue
1 \
alities Exterr
alities
i
'\
Final
Disposition
'
alities
Figure 3-3. Life-Cycle Costing (as presented in SETAC (SETAC, 2009))
As with an LCA, LCC is a process-based method, accordingly boundaries must be set around the
product system. To connect the analysis to the broader economy-level, LCC inputs and outputs
may be combined with an economic input/output database. The resulting hybrid analysis allows
the interconnections between the product system and the rest of the economy to be accounted for
without compromising the level of detail.
Other methods such as total cost accounting (TCA) and total cost of ownership (TCO) may also
be used to account for the costs of a product system. Although these methods do not consider
both internal and external (societal) costs, they may be beneficial for estimating the costs for
certain stages of LCC analysis. For example, total cost accounting may be used to estimate
production costs for development of a nanoproduct from the manufacturer's perspective and total
cost of ownership may be applied to estimate the costs incurred by a consumer during the use,
maintenance, and end-of-life stages. As in LCA, LCC can be applied to specific stages of the
product.
Total cost accounting (TCA) is concerned only with costs to the company itself and
examines all the costs that go into making a product, including activities from R&D to sales.
TCA can encompass any combination of business activities.
.. — ^
Manuf
icturmg r
Marketing
1
Source: Finding Cost Effective Pollution Prevention Initiative (Global Environment Management Initiative)
-------
Table 3-2 summarizes the economic assessment methods most relevant to nanoproducts. The
table does not include non-hybrid economic input-output models, general equilibrium models, or
partial equilibrium models, because these tools primarily assess meso- and economy-wide
changes, and are not as applicable to nanoproducts.
Table 3-2. Key Economic Assessment Methods
Method Description/ Scope/ Impacts Reference
Benefits Stage Measured
Life Cycle
Costing
(LCC)
Eco-
Efficiency
Analysis
Assesses the comprehensive
costs of a product throughout its
life cycle stages. LCC may apply
techniques such as Total Cost
Accounting, Activity-Based
Costing (ABC), or Total Cost of
Ownership to estimate and
allocate costs between
manufacturers, consumers, and
society.
Combines Environmental Life-
cycle Assessment with Total
Cost of Ownership to draw a
relationship between the
economic value of a product and
its environmental impacts.
Product/
micro level
All life cycle
stages
Product/
micro level
All life cycle
stages
Cost to
manufacturer and
consumer per
functional unit
(service of
product)
Ratio of
economic value
of a product
(from a consumer
perspective) to
the life cycle
environmental
impacts (e.g.,
energy and
material
consumption,
waste, air, and
water emissions).
(Hunkeler et
al., 2008;
SETAC,
2009)
(Saling et
al., 2002;
White etal.,
1995)
3.2.1 Data Sources for Economic Assessments
Life cycle costing requires data for not only the direct cost factors but also indirect costs, as well
as costs related to liability and less tangible benefits. While it may be easier to obtain data on
direct costs, it may be more problematic to estimate potential future costs. Following are ways by
which these costs may be tracked.
3.2.2 Issues Related to Economic Assessment Methods
High research and development costs. Nanoproducts are an emerging technology, and involve a
great deal of research and development. Even though material use during research and
development may be low, the costs during this phase often constitute a large amount of overall
product costs. As a result, the economic assessment may include the "knowledge" phase, e.g.
research and development and acquisition via the supply chain. Other elements, such as
marketing activities, might also be included in the assessment (SETAC, 2009).
Fluctuating manufacturing and capital equipment costs. Costs associated with a nanoproduct
may fluctuate as the technology matures, depending on several factors, including changes in
43
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technology design and resources needed for capital equipment. Given the quickly evolving
production processes for nanotechnologies, capital equipment may become outdated more rapidly
than for other technologies. Furthermore, some costs may be sensitive to production volume due
to economies of scale, while other costs are rather stable (SETAC, 2009). If capital equipment is
included use of a hybrid economic input-output model would sufficiently capture impacts from
capital equipment. Alternatively, instead of EIO data, if more precise data is available, an
evaluation of capital equipment could be nested within the larger assessment when appropriate
and feasible.
Limited consumer and end-of-life cost data. In many cases, there is a high degree of uncertainty
for emerging technologies regarding future costs during the use and end-of-life stages. If cost data
from the use and end-of-life stages are limited, it still may be possible to conduct an assessment
solely from the manufacturer's perspective. Such an assessment would not be comprehensive, but
could still provide valuable information for an LCC. Cost data on use and end-of-life could be
incorporated into the assessment at a later date when the product goes to market or when
additional information becomes available (SETAC, 2009). Identification of costs that may change
over time or by region (e.g., energy costs) are also important as it may impact the economic value
of the product for the consumer (SETAC, 2009). In addition, it is possible to estimate future costs
based on costs for similar products. For example, the cost to recycle a nano-based lithium ion
battery may be similar to the cost of recycling a lithium-ion battery that does not contain
nanomaterials. Any information about the uncertainty surrounding the predictions of future costs
should be incorporated into an uncertainty analysis.
Uncertainty regarding product lifetime and selecting an appropriate discount rate. Given
potential uncertainties in the lifetime of the product and/or when a product may come to market,
it may be difficult to determine an appropriate discount rate (SETAC, 2009). Discounting is used
to account for the time-value of money and brings future costs to a present value. Therefore,
selection of an appropriate discount rate is crucial for estimating future costs (SETAC, 2009).
SETAC (SETAC, 2009) provides guidelines for selecting a discount rate depending on the
stakeholder perspective (e.g., bond rate, lending rate, or weighted average cost of capital). In
addition, a sensitivity analysis should be considered to assess the impacts of a range of
appropriate discount rates.
Uncertainty regarding economic benefits/costs. Developing nanotechnologies may lead to great
benefits for society, such as improved military or medical technology, more efficient use of
resources, and more reliable devices. However, these benefits might be accompanied by negative
consequences. For example, improved medical care could increase healthcare budgets, because
money spent on healthcare ultimately succeeds only in shifting the expenses involved in keeping
individuals alive to a later date. The longer people live, the more expensive it is to keep them
alive. Moreover, years added to the end of life are likely each to be quite expensive (Sparrow,
2009). There is a great deal of uncertainty surrounding the potential effect that nanoproducts will
have on the economics of medical devices and health care costs, which makes it difficult to
incorporate these concerns into an economic or social assessment. However, if there is reason to
believe that the nanoproduct in question will affect a segment of the economy (e.g., healthcare),
it may be worthwhile to at least include a qualitative discussion of the potential impacts. A
qualitative assessment may be enough to facilitate a discussion with stakeholders during the
decision analysis phase of the assessment.
Delineation between external versus internal costs. Given the high degree of uncertainty
regarding nanoproduct properties, potential environmental impacts, and future regulations, some
costs may be difficult to identify and estimate, such as future costs of remediation, or the
44
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reclassification of waste produced by the firm to hazardous (SETAC, 2009). This issue is
essentially one of externalities. Even though governments and society generally do not directly
cover costs in the product system, sometimes they do indirectly cover them (e.g. costs to
construct and maintain roads near a production facility, impact of air emissions on human health).
These external costs should not be included in the economic assessment to avoid double counting
impacts. However, if it's anticipated that an external cost may become internalized, either through
taxes, fees, or new regulations, then it may be appropriate to include such costs in the study, and
to conduct a sensitivity analysis around them (SETAC, 2009).
Uncertainty regarding impacts on other economic sectors. If the nanoproduct has the potential
to develop into a general purpose technology, previous experience suggests that the effects on
productivity and economic growth could be significant even though these may sometimes come
with a more significant time lag (Palmberg et al., 2009). Given the high level of uncertainty
regarding the potential of various nanotechnologies to be transformed into general purpose
technologies, it may not be possible to quantitatively assess the broader economic benefits and
impacts associated with a new nanoproduct. In other words, it is very difficult to predict if and
how an emerging technology will enable the development of other technologies (Palmberg et al.,
2009).
Even so, if there is some evidence that the nanoproduct in question will enable the development
of other products, it may be worthwhile to at least qualitatively consider the potential economic
implications, such as increased or new demand for certain materials, job creation, and economic
growth. For example, increased demand for high-tech materials might increase the number of
jobs available to the high-tech workforce. The bulk of nanotechnology firms are based in
developed countries, particularly the United States, (Palmberg et al., 2009). Accordingly, many of
the newly created high-tech jobs might also be located in developed countries.
Uncertainty regarding impacts on incumbent firms. Some nanotechnology-based advances will
build upon or be readily integrated with existing technologies manufactured by "incumbent"
firms. In such cases, adjustment to the new technology by incumbent firms is expected to be
relatively smooth. Other nanotechnology based innovations will involve radically different
processes, in turn destroying the competencies of existing firms with the potential of reallocation
of economic activity to different firms and regions of the nation or globe (Shea, 2005). While it
can be difficult to determine ex-ante the impact of an emerging technology on existing
competencies, it may be possible to draw qualitative conclusions. Table 3-3 presents a summary
of observations that may aid in providing qualitative assessments regarding whether a nano-based
innovation is more or less likely to result in decline in economic performance of the incumbent
firm (Shea, 2005).
Table 3-3. Example Factors Impacting Incumbent Firms
Factors more likely to negatively
impact incumbent firms:
Nanotechnology-based innovations that
are complex or where only limited
information is available.
Nanotechnology-based innovations that
constitute a change to a process or
component that is core to the whole
product system.
Bottom-up fabrication techniques (e. g.,
Factors less likely to negatively impact incumbent firms:
Incumbent firm's existing technologies are reaching the
limits of their life cycle curve, resulting in increased
incentive to adopt new technologies.
Incumbent firm has complementary assets to take
advantage of the nano-based innovation. Complementary
assets can range from technical knowledge to
relationships with distributors and consumers.
Incumbent firm engages in inter-firm cooperation to keep
45
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based on emerging chemistry
techniques) as opposed to top-down
techniques (e. g., use of existing
lithography techniques).
abreast of nanotechnology-based developments.
Incumbent firm has a strong ability to exploit external
knowledge relevant to nanotechnology-based innovations.
3.2.3 Challenges in Conducting Economic Assessments
The term 'economic assessment" has many meanings and uses. It can refer solely to the costs that
directly influence a manufacturer's bottom-line (private costs) or it can be expanded to include
the costs to individuals, society and the environment (total costs). Specific economic assessment
issues or challenges vary depending on the scale of the application. Accounting for conventional,
private costs is a fairly straightforward process. Life cycle costs which do not have a direct
impact on a company's bottom-line, are harder to model. However, businesses will ultimately
benefit from moving toward including probabilistic and difficult to estimate costs in their
business decisions.
It is important to ensure that environmental impacts are not "double counted" when applying the
impact models of LCA and LCC. To avoid double-counting costs, LCC avoids the monetization
of external costs that are environmental impacts not paid for directly or indirectly by the product
manufacturer (e.g., the potential monetary costs caused by losses due to greenhouse gas emission
and the resulting global warming) (SETAC, 2009) . In addition, when conducting both a LCA and
LCC, it is important to use equivalent system boundaries and the same functional unit
(SETAC, 2009). However, it is possible that some components or processes of a product system
would be included in one assessment and not another (or vice versa), because some aspects could
have high costs but low material flow. For example, while the cost of research and development
may be high, the material flow and costs may be relatively low once in full production mode. In
this case, research and development costs might be included in the LCC, but research and
development materials would not be included in the LCA.
3.3 Social Assessment Methods
While methods for assessing the social impacts of a product are not as mature as methods for
assessing environmental and economic impacts, concerns about social responsibility are
increasing and should not be overlooked (ISO, 2009; Jorgensen et al., 2008). Several initiatives
and organizations, as well as the international community, have given thought to the underlying
core values, principles, and standards that should guide social assessments, and researchers are
actively developing methods for applying these principles and standards to products.
Given the nascent stage of social sustainability assessment and the lack of well-developed
methods, this section describes principles and standards relevant to social sustainability, as well
as the currently available methods for applying those standards. In addition, we describe potential
issues and decision factors that may arise when applying these standards to nanoproducts.
The International Organization for Standards (ISO) is in the process of developing the Guidance
on Social Responsibility, which "provides guidance on the underlying principles of social
responsibility" (ISO, 2009). This document was released as a draft international standard in
September 2009 and was advanced to a final draft international standard in March 2010. Other
organizations have also developed internationally recognized standards for social accountability,
which can be used in social sustainability assessment. These include Social Accountability
International's facility level SA8000 standard (SAI, 2008), AccountAbility's AA1000 enterprise
level series of standards (AccountAbility, 2008), and the Global Reporting Initiative's supply
46
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chain level reporting guidance (GRI, 2006). Researchers and analysts are currently working to
incorporate these principles and standards into assessment methods, including existing life cycle
assessment methods.
In an effort to create a central framework for adapting ISO 14040 and 14044 to social criteria, the
United Nations Environmental Program (UNEP) together with the Society for Environmental
Toxicology and Chemistry (SETAC) published the Guidelines for Social Life Cycle Assessment
of Products through the Life Cycle Initiative (UNEP, 2009a). The UNEP/SETAC guidelines pull
together and build upon much of the existing literature to provide a framework for Social Life
Cycle Analysis (SLCA). These guidelines recommend that impact categories be based on
internationally accepted standards, such as SA8000 (SAI, 2008) and AA1000 (AccountAbility,
2008). The UNEP/SETAC guidelines also suggest following the requirements of the Voluntary
Quality Standard for SRI Research (CSRR-QS, 2010) to gather data on upstream suppliers.
The basic components of an SLCA are the same as for an LCA described in Section 3.1. There is
a difference, however, in the type of data collected. As illustrated in Figure 3-4, whereas a LCA
requires data on process and material flows, SLCA requires data on how companies in the supply
chain interact with stakeholders, such as employees, local residents, the broader community,
society at large, and other persons affected by the company's actions (Dreyer et al., 2006;
Hauschild et al., 2008). Furthermore, SLCAs must typically include geographic information,
because social assessments must take into account conditions specific to companies and
geographic areas, such as worker safety, environmental justice, access to resources, etc (Dreyer et
al., 2006; Swarr, 2009). The local/regional nature of some social impact pathways also creates a
high degree of uncertainty when calculating impacts with methods built upon aggregate data,
such as traditional LCA methods (Klopffer, 2008; Norris, 2006). As an alternative, certification
systems, such as fair trade programs, may be used to determine whether materials in the supply
chain meet certain standards, such as fair wages and safe and just working conditions (Norris,
2006). Norris introduced the Life Cycle Attribute Analysis (LCAA) to calculate the amount of
output from a supply chain that has an attribute of interest. Attributes could be any quality
relevant to the assessment, such as fair trade labels (Norris, 2006).
Raw Materials
Extraction
Company
H"
l»
r ~\
Materials
Processing
Company
ir
i^
Product
Manufacturing
Company
T
If
Use and
Maintenance
Company
ir
•»
^ -\
End of Life
(EOL) Actors
ir
Stakeholders (e.g. employees, community members, consumers)
V ^
Figure 3-4. Social Life-Cycle Assessment (Dreyer and Hauschild, 2010)
Some impacts estimated as part of an environmental assessment may also be considered in a
social assessment, but care should be taken not to double count impacts. For example, human
health impacts (e.g., cancer human toxicity) for both the public and workers may be considered a
social impact. If an impact is included as part of the social assessment, then it should not also be
included as part of the environmental assessment.
Social Impact Assessment (SIA) and Social Assessment (SA) are other methods commonly used
to analyze social impacts. However, these methods were developed to complement
Environmental Impact Assessment, and apply more to larger scale meso and economy-wide
projects. The United States Department of Agriculture describes SA as "the basis for identifying
and forecasting consequences of possible projects or policies" (Alan et al., 2003). Similarly, the
47
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SIA community describes SIA as a method for "analyzing, monitoring and managing the social
consequences of development" (Vanclay, 2003). While the methods of SIA apply more to larger
scale projects and interventions, the guiding core values and principles are equally applicable to
products. These principles are laid out by Vanclay (Vanclay, 2003). Table 3-4 shows the social
assessment methods most relevant to nanoproducts.
Table 3-4. Key Social Assessment Methods
Method Description/ Scope/ Impacts Measured Reference
Benefits Stage
Social Life-
Cycle
Analysis
(SLCA)
Life Cycle
Attribute
Analysis
SocioEco-
Efficiency-
Analysis
Assesses the
social aspects of
products and
their impacts
along their life
cycle.
Calculates the
amount of total
output that has
the attribute of
interest (e.g. fair
trade
certification)
Provides an
assessment of
societal impacts,
as well as
environmental
impacts and
economic costs.
Product/micro
level
All life cycle
stages
Product/micro
level
All life cycle
stages
Product/micro
level
All life cycle
stages
Defined by the stakeholders.
For example:
• Human rights
• Working conditions
• Cultural heritage
• Poverty
• Disease
• Political conflict
• Indigenous rights
Amount or percent of output
that:
a) Has the attribute of
interest;
b) Lacks the attribute of
interest; or
c) Lacks data on attribute
status
• Environmental
• Economic
• Social (e.g., number of jobs,
number of working
accidents occurring during
production).
(Dreyeretal.,
2006; Jorgensen
etal.,2008;
Swarr, 2009;
UNEP, 2009a;
Weidema, 2006)
(Klopffer,
2008; Norris,
2006)
(BASF, 2011;
Klopffer, 2008)
In addition to the methods presented, some computable general equilibrium (CGE) models and
partial equilibrium models (PEMs) incorporate social aspects (Zamagni et al., 2009). However,
these models address the meso and economy-wide impacts, and are not expected to be relevant to
nanoproduct design and manufacture.
3.3.1 Data Sources for Social Assessments
Generally, practitioners of SLCA will need to incorporate a large share of qualitative data, since
models for interpreting the numeric information related to the social issues being addressed are
not well developed. When numeric data is useful—for example, in assessing the wages of a
particular enterprise—additional data will still be needed to address its meaning. For example,
compliance with minimum wage laws does not always mean that the wages are livable. Often,
48
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data may need to be collected to represent site-specific situations, since databases for specific
social and socio-economic impacts are at a minimum (UNEP, 2009a).
The Social Hotspots Database, a project of New Earth, was created in 2007 by Catherine Benoit
and Greg Norris (Benoit and Norris, 2007). The idea began during their work on the Guidelines
for Social Life Cycle Assessment of Products, published by UNEP (UNEP, 2009b), when Benoit
and Norris noticed opportunities for improvement in Life Cycle databases. Most LCA tools lack
the ability to specify the geographical location of production activities -information that is
essential for social impact assessments. The Social Hotspots Database can play a role similar to
LCA databases in assessing product hotspots, but with the added benefit of geographical
precision and potential social impacts identification. The development of the database started in
September 2009.
The Social Hotspots Database allows for visibility in the supply chain by:
• Providing modeling of product life cycles by country specific sector.
• Providing estimates on where the people are in the product's supply chain and what
specific risks and opportunities might affect them.
• Expressing quantitatively the share of a supply chain where specific hotspots are found.
It shows which country specific sectors represent the greatest share of worker hours in a given
supply chain, which ones are the most at risk of human rights and social issues, and which ones
can represent business opportunities to implement positive changes in livelihood.
3.3.2 to
Uncertainty regarding social impacts. Like all emerging technologies, it will be difficult to
assess the social impacts of nanoproducts before they have been on the market. Nanotechnologies
have the potential to deliver considerable benefits to society, but at the same time these products
may pose great risks (Walsh et al., 2008). Much of the risks that have concerned researchers to
date are issues of toxicity, yet there may be other risks, as well. For example, will disposal and/or
recycling of the nanoproducts be associated with poor working conditions? This raises further
questions regarding the scope of a social assessment done from the developer's and
manufacturer's perspectives. For example, to what extent should such assessments take into
account downstream practices that might be out of the manufacturer's control? Although the
answers to the questions are not yet fully resolved, they should be considered even as part of a
qualitative analysis (Dreyer et al., 2006).
Inadequate methods for addressing high levels of uncertainty. As described above, for
nanoproducts, there are likely to be multiple layers of uncertainty. As a result, traditional
approaches to quantifying uncertainty, such as Monte Carlo analysis, might be inadequate (Seager
and Linkov, 2008). Probability distribution under conditions of extreme model and boundary
uncertainty lack meaning (at best) or may lead to overconfidence (at worst). To address these
uncertainties a scenario analysis could be conducted, thereby affording the ability to consider
possible future activities, events or even policy decisions, such as market expansions, resource
availability, use, technology improvements and production caps). This allows product developers
to explore sensitivities and possibilities while gaining a feel for trade-offs (Seager and Linkov,
2008).
49
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3.3.3 in
The conduct and implementation of social responsibility assessments is relatively new and poses
complex challenges. The choice of which approach is appropriate will be application specific.
Different contexts will represent different challenges and will need varying levels of assessment.
Some developed countries may already cover many of Human Rights and Worker Rights
indicators and the application of the law may be well executed. However, developing countries
may not be at this same level. For example, in many cases, enterprises in developed countries are
not allowing freedom of association. Therefore, as part of the assessment, screening for minimum
compliance when thresholds exist, and possibly also to assess performance beyond compliance
thresholds, is suggested. The elements that should be defined in the goal definition phase of the
assessment and accounted for in the interpretation phase of the study. Comparative studies must
be conducted with the same level of assessment (UNEP, 2009a).
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4. Assessing Sustainabilitv
In Section 3, we provided a summary of methods for evaluating the environmental, social and
economic impacts of the product system over its lifetime. The result of these assessments is an
inventory of indicators computed and compiled based upon the established sustainability criteria.
The data alone can provide some insights regarding the nanoproduct to include identifying the
processes with the greatest impacts, prioritizing approaches for impact reduction and improving
the product system. However, it typically is very difficult to determine which approach is better
due to complex tradeoffs. For example, a company may be considering three different synthetic
processes for manufacturing silica nanoparticles, each of which are technically and economically
feasible, environmentally sound and socially responsible. Hence, while data may be plentiful,
critical knowledge to guide decision making is scarce (Klimberg and Miori, 2010). Further, note
that while making decisions based on one facet alone is challenging, when coupled with the
unique intricacies of handling multiple factors inherent in sustainability, the difficulty of decision
making skyrockets. In this section, formal decision analysis methods are discussed which may be
used within the context of sustainability to systematically organize information, make sense of the
problem and select the preferred option.
4.1 Evaluating Sustainability Criteria
To illustrate the complexity of decision making, we highlight some of the critical elements that
are important for assessing nanomaterials. Key characteristics include agglomeration and
aggregation, reactivity, physical form/shape, solubility, surface area, critical functional groups,
contaminant dissociation, bioavailability, bioaccumulation potential and toxic potential (Tervonen
et al., 2009). These elements are primarily related to risk, however when assessing the
sustainability of nanoproduct production, information such as energy use, material use,
environmental impacts, human health impacts and cost should also be considered. Based upon
preferences, values and objectives, the criteria for comparing each alternative are established by
stakeholders and decision makers. Figure 4-1 is a mapping of decision criteria considered by
Canis et al. (Cam's et al., 2010) in their comparative assessment of alternatives for single walled
carbon nanotube (SWCNT) synthesis. Note that life cycle impact assessment (LCIA) score and
health risks are proxy measures which compile multiple indicators related to environmental and
human health impacts. In the study, data were gathered to populate the measures for each
synthesis method by extrapolating from existing studies and expert opinion. Even with data in
hand, making a decision also requires deciphering the views of stakeholders who typically
have diverse goals, priorities and values. Hence, the question now becomes: How is one
alternative selected over another?
There are numerous studies that evaluate sustainability based on multiple criteria (e.g., (Bailey et
al., 2010; Eason et al., 2009; Halog and Manik, 2011; Hopton et al., 2011; Linkov et al., 2006;
Sikdar and Murray, 2010)), yet not all utilized a formal decision strategy. Further, while decisions
may be made from simplified approaches, such methods tend to minimize complexity and
consequently lose some crucial details (e.g., uncertainty) necessary for making informed, high
quality decisions (Linkov et al., 2004; McDaniels et al., 1999). Merkhofer (Merkhofer, 1999)
describes the characteristics of quality decision making as decisions that involve the key
stakeholders, contains relevant types and amount of information, identifies good alternatives,
provides logically sound results and properly integrates the preferences of the decision makers.
Accordingly, it is critical that methods be implemented that have the ability to integrate pertinent
information and help guide decision making. Table 4-1 is a snippet of the list Merkhofer
(Merkhofer, 1999) presented which displays the scope of various tools that have been developed
to aid in evaluating, refining and selecting desirable alternatives. The scope is defined by the
51
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Criteria
Energy
Consumption
(GWh/kg)
Material Efficiency
(% in mass)
LCIA Score
(EcoPoints)
Cost ($/g)
Health risks
Alternatives
HiPco
CVD
Arc
Laser
Figure 4-1. Mapping the Decision Criteria: Sample Criteria for Assessing Single-Walled
Carbon Nanotube Synthesis Processes (Canis et al., 2010) HIPCO: High Pressure
Carbon Monoxide; Arc: Arc Discharge; CVD: Chemical Vapor Deposition; Laser: Laser
Vaporization.
52
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Table 4-1. Sample Decision Making Tools (Merkhofer, 1999)
Tool
Analytical Hierarchy Process
Cost-Benefit Analysis
Decision Analysis
Environmental Impact
Assessment
Probabilistic Risk Assessment
Structured Voting
Classical Probability Models
Primary Uses
Problem
Definition
Assessing
health or
environmental
risks
Assessing
other risks
Determining
whether
action is
needed
Collecting
information
Screening
alternatives
Identifying
alternatives
Evaluating
Alternatives
Selecting
Options
Communicating
decisions
53
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primary uses within decision making. For example, while cost-benefit analysis may be used for
the full gamut of the decision making process from problem definition to communicating
decisions, Analytical Hierarchy Process is typically only used to aid in problem definition,
screening and evaluating alternatives and selecting options. Although, both decision analysis and
cost-benefit analysis cover the scope of decision support needs, cost-benefit analysis only truly
accounts for one of the pillars of sustainability, is primarily based on market prices and typically
has very little stakeholder interaction.
Decision theory is a field of study that aids in formulating hypotheses based on values, risk,
uncertainty and tradeoffs. It relates to techniques to aid decision makers in determining the best
option when the outcomes are uncertain and the decision environment is unpredictable (Parsons
and Wooldridge, 2002). Decision theory is compartmentalized into two primary genres:
normative and descriptive. While descriptive decision theory is rooted in experimental
psychology and deals with determining how and why people make decisions, normative decision
theory is prescriptive and relates to finding the best decision (Peterson, 2009). Decision analysis
(DA) is under the banner of decision theory and is a systematic approach to evaluating complex
problems and enhancing the quality of decisions (Clemen and Reilly, 2001). The basic steps of
DA include: problem identification, information gathering, generating possible solutions,
evaluating and selecting solutions. The DA flowchart provided in Figure 4-2 expands these basic
steps to incorporate estimating baseline risk, decomposition and modeling, sensitivity analysis
and a recursive step to account for further analysis when developing and analyzing new
alternatives.
Many researchers have noted the benefit of applying decision analysis to life cycle approaches
and highlight the similarities between the two structures (Seppala et al., 2002). Accordingly,
when referring to Figure 1-2, note that rudiments of the decision analysis process are dispersed
throughout the framework. Since Sections 2 and 3 contain elements of the initial steps of decision
analysis, once we reach this section of the guidance structure, the product has been characterized
and stakeholders have been identified. In addition, the objectives, goal and scope of the study and
an inventory of indicator data have been compiled for each alternative. Hence, the focus at this
point is to take the indicators and use them to make informed decisions. The DA approach was
modified to reflect this aim and consists of evaluating and interpreting impacts, determining
preferences and uncertainty, selecting the most sustainable alternative and sensitivity analysis
(Figure 4-3).
At its core, DA aids in reconciling conflicting values, objectives and preferences with the aim of
reaching a wise, informed decision (Keeney and Raiffa, 1976). More accurately, it relates to
handling problems that are characterized by complexity, uncertainty, risks and tradeoffs. As
described in Section 3, there is likely to be a great deal of uncertainty related to the sustainability
of emerging technologies. Characterizing and dealing with these uncertainties will be a major
challenge in any decision putting a premium on decision analysis methods that handle uncertainty
in an explicit and transparent manner. The presence of uncertainty coupled with multiple
attributes describes what Keeny and Raiffa (Keeney and Raiffa, 1976) denote as "the double
dichotomy of decision problems." Uncertainty is discussed further in Section 4.4.
54
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Define problem and
identify objectives
Estimate baseline risk
Identify alternatives
Collect information
related to
alternatives
Decompose and model the problem
1. Model problem structure
2. Model uncertainty
3. Model preferences
Choose the
best alternative
Is further
analysis
needed?
Implement
the chosen
alternative
Figure 4-2. Decision Analysis Flowchart (Clemen and Reilly, 2001; Merkhofer, 1999)
JJ
-------
Assessing
Sustainability
\
\
Evaluate Sustainability
Criteria
N.
Select the best
alternative
Sensitivity Analysis
Yes
No
1
Implement the
chosen
alternative
Figure 4-3. Modified Decision Analysis (DA) Approach
Table 4-2 provides information (to include stakeholder input) on some of the most common
decision making strategies. Ad hoc approaches typically have very limited stakeholder input and
contain criteria that often are not explicitly defined. In addition, alternatives are evaluated through
qualitative or semi-quantitative measures and the final selection is often not transparent. Further,
the weighting schemes are often developed by the decision maker and are not sufficiently
justified. Cost-benefit analysis (CBA) and probabilistic risk assessment (PRA) have explicit
evaluations schemes, a great deal of stakeholder input and are useful in many cases. However,
these methods relate primarily to cost and risk respectively, but are limited in their ability to
56
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Table 4-2. Comparison of Process Elements for Common Decision Making Tools (CALCAS, 2008; Linkov et al., 2006; Merkhofer, 1999)
Define problems
Generate alternatives
Formulate criteria by which
to judge alternatives
Gather value judgments on
relative importance of
[criteria
Rank/select final alternatives
Stakeholder input limited or non-
existent. Therefore, stakeholder
concerns may not be addressed
by alternatives
Alternatives are chosen by
decision-maker usually from pre^
existing choices with some
ejgjertjnrjut.
Criteria by which to judge
alternatives are often not
explicitly considered and
defined.
Non-quantitative criteria
valuation weighted by decision-
maker
Alternative often chosen based
on implicit weights in an opaque
manner
Stakeholder input collected after the problem is
defined by decision-makers and experts.
Problem definition is possibly refined based on
stakeholder input.
.Alternatives are generated through formal
involvement of experts in more site-specific
manner.
Criteria and sub-criteria are often defined.
Quantitative criteria weights are sometimes
formulated by the decision-maker, but in a
poqrlyjustified_ma!lS§L
Alternative chosen by aggregation of criteria
scores through weight of evidence discussions
or qualitative considerations.
Stakeholder input incorporated at beginning of problem
formulation stage. Often provides higher stakeholder
agreement on problem definition. Thus, proposed
solutions have a better chance at satisfying all
stakeholders.
Alternatives are generated through involvement of all
stakeholders including experts. Involvement of all
stakeholders increases likelihood of novel alternative
generation.
Criteria and sub-criteria hierarchies are developed
based on expert and
stakeholder j udgment.
Evaluation of total expected costs vs.
total expected benefits; Criteria often
based on various economic meausre to
include: net present value, benefit,
benefit to cost ratio, etc.
Quantitative criteria weights are obtained from decision-
makers and stakeholders.
Alternative chosen by systematic, well-defined
algorithms using criteria scores and weights.
Typically defined by decision makers
Alternatives often generated by a
limited group of stakeholders and
decision makers
Preferences are not necessarily made
explicit or considered
Based upon costs and benefits
Strength
Simple and low cost
Systematic means of exploring and quantifying
risk; good documentation,quantifies
uncertainty, identifies threats
Ability to handle complex decisions with mutiple
criteria and stakeholders with multiple viewpoints;
Decision making in concert with stakeholder values and
preferences; strong theorectical foundation; can handle
soft issues (e.g., social) and uncertainty
Strong theoretical foundation with tools
to aid in estimating (cost and benefits);
common unit of measure; helps
managers allocate limited resources;
not everything can be monetized
Weakness
Inflexible, can not handle
complexity or uncertainty, not
reproducible, no logic or audit
trail, limited stakeholder
involvement; therefore, not all
concernsconfiidemd
Difficult, expensive and time consuming;
Possible inacuracies due to estimating and
assumptions on mechanisms that are not well
known leading to large uncertainties and
misleading results
Typically time consuming
Often limited stakeholder interaction;
deals with net impacts and not who
pays the costs or reaps the benefits,
typically based on market prices and
not true preferences
57
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handle the broad aspects of sustainability. On the other hand, multi-criteria decision analysis
(MCDA) can handle the diverse elements of sustainability and affords the ability to make
decisions based upon active stakeholder input from the beginning to include developing
objectives, criteria and alternatives. Moreover, the weights are determined by querying both
decision makers and stakeholders to determine their preferences and the final alternatives selected
are determined systematically.
4,3 the
It is expected that the development of sustainable nanoproducts will involve a finite number of
alternative approaches. Accordingly, this section provides an overview of methods designed to
handle the evaluation of multiple criteria (e.g., multiple impact categories) for multiple
alternatives. These methods are commonly referred to as multi-criteria decision analysis (MCDA)
(Cohon, 2003). The application of MCDA approaches has grown dramatically in the last twenty
years, particularly in the environmental arena and has been used to support decisions in multiple
areas including waste management, energy, sustainable engineering and manufacturing, natural
resources, energy, product comparisons, policy decisions and remediation (Huang et al 2011).
Hence, MCDA may provide a sound framework for assessing nanomaterials and products.
MCDA methods typically synthesize the criteria and select alternatives based upon techniques
such as: ranking options, identifying a single optimal alternative, incomplete ranking, or
differentiating between acceptable and unacceptable alternatives (Kiker et al., 2005). The primary
MCDA approaches are: Multiple attribute decision analysis (MADA) and Multiple Objective
Optimization (MOO). While, MADA is applied when the decision relates to evaluating a finite
set of alternatives, MOO is an operations research approach and is often implemented when the
possible solution set is infinite and/or contains continuous variables. Examples of these
approaches may be found in Seppala (Seppala, 1999) and Azapagic and Clift (Azapagic and Clift,
1998). Since, the framework will involve the assessment of a finite number of alternatives, we
will focus on MADA approaches. Further descriptions of these methods may be found in Stewart
(Stewart, 1992), Chen and Hwang (Chen et al., 1992), Norris and Marshall (Norris and Marshall,
1995) and Guitoni and Martel (Guitoni and Martel, 1998).
Some of the most relevant MADA approaches are summarized Table 4-3 and include outranking,
multi-attribute utility theory (MAUT) and analytical hierarchy process (AHP). These approaches
not only aid in selecting an alternative, but all of them except outranking can be used to evaluate
impacts. However, all of the methods are at least partially compensatory which indicates that low
scores in one criterion can be compensated for by high scores in another. When performing a
sustainability assessment, it is important to note that in order for a product to be sustainable, it
must meet the established criteria within each of the three sustainability pillars - environment,
economy, and society. Accordingly, some would argue that while components of sustainability
are integrated, benefits in one aspect of sustainability do not compensate for detriments in
another. Hence, care must be taken when using compensatory approaches. A list of some of the
commercially available decision support tools is provided by Azapagic and Perdan (Azapagic and
Perdan, 2005) and Kiker et al. (Kiker et al., 2005). Linkov et al. (Linkov et al., 2006; Linkov et
al., 2004) provide an extensive record of studies that applied MCDA and decision support tools in
environmental decision making.
58
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Table 4-3. Summary of Common Multi-Criteria Decision Analysis (MCDA) Methods
Method Description
Elementary Non compensatory method with no
requirement for quantitatively evaluating
criteria trade-offs; Ranking may be based
upon: the strength of the weakest or
strongest link, attributes meeting
predetermined thresholds, or best
performance on attributes with t
Reference Approaches
No weighting is required
Requires attributes to be on
a common scale;
(Seppala et al,
2002; Yoon and
Hwang, 1995)
Maximin, Maximax,
Conjunctive, Disjunctive and
lexicographic
Multi-Attribute
Utility Theory
(MAUT)
Compensatory method in which the
overall score for each alternative is based
on relative weights; Weights typically
determined by surveying stakeholders and
generated by utility functions
(1) Easier to compare alternatives
whose overall scores are expressed as
single numbers. (2) Choice of an
alternative can be transparent if highest
scoring alternative is chosen. (3)
Theoretically sound — based on
utilitarian philosophy (4) Many people
p refer to express net utility in non-
monetary terms.
(1) Maximization of utility
may not be important to
decision makers. (2)
Criteria weights obtained
through less rigorous
stakeholder surveys may
not accurately reflect
stakeholders' true
preferences. (3) Rigorous
stakeholder preference
elicitations are expensive.
(Baker etal,
2001; Clemen,
1996;
Wolfslehner,
2008)
Multi-value utility theory
(MAUT), Simple Multi-
Attribute Rating Technique
(SMART)
Outranking
Partially compensatory methods that
determines the extent to which one
alternative dominates another. It allows
options to be classified as "incomparable"
(1) Does not require the reduction of all
criteria to a single unit. (2) Explicit
consideration of possibility that very
poor performance on a single criterion
may eliminate an alternative from
consideration, even if that criterion's
performance is compensated for by very
good performance on other criteria
performance (3) It is easy to explain.
The algorithms used in
outranking are often
relatively complex and are
often not well understood
by decision-makers.
(Kiker et al.,
2005; Linkov et
al., 2007; Naidu
et al., 2008a;
Seager and
Linkov, 2008;
Wolfslehner,
2008)
Preference Ranking
Organization METHod for
Enrichment Evaluations
(PROMETHEE), Elimination Et
Choix Traduisant la Realite
(ELECTRE) (Kangas et al.
2001) and Novel Approach to
Imprecise Assessment and
Decision Environments
(NAIADE) software
Analytical
Hierarchy
Process (AHP)
Compensatory method in which the
overall score for each alternative based on
relative weights. Weights are generated
by a series of pair-wise comparisons. . It
is the most widely used approach of the
MCDA methods.
Surveying pairwise comparisons is easy
to implement
The weights obtained from
pairwise comparison are
strongly criticized for not
reflecting people's true
preferences
(Huang etal.,
2011; Kiker et
al., 2005; Linkov
et al., 2007;
Saaty, 1988;
Seager and
Linkov, 2008)
AHP
59
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Additional details on applying MCDA approaches for assessment of nanomaterials can be
obtained from literature (Cam's et al., 2010; Linkov and Seager, 2011; Tervonen et al., 2009).
Outranking and aggregated weighted approaches (e.g., multi-attribute utility theory and analytical
hierarchy process) are discussed in the following sections.
4.3.1 Outranking
Outranking is the least compensatory of the methods presented and involves pair-wise
comparison between alternatives (i.e., one criterion at a time) to determine the extent to which
one alternative is preferred over the other. For example, outranking methods may select the
product alternative that meets the minimum requirements and results in the greatest impact
reductions for the greatest number of criteria. Outranking methods are most appropriate when the
criteria are not easily aggregated, measurement scales vary over wide ranges, or units are
incomparable (Kiker et al., 2005; Linkov et al., 2007; Seager and Linkov, 2008). Outranking
methods include Preference Ranking Organization METHod for Enrichment Evaluations
(PROMETHEE), Elimination Et Choix Traduisant la Realite (ELECTRE) (Kangas et al., 2001)
and Novel Approach to Imprecise Assessment and Decision Environments (NAIADE) software
(Naidu et al., 2008b)). While outranking methods are easy to explain, they consist of complex
algorithms that are often not well understood by decision makers.
Example - Outranking (Naidu 2008)
Sasikumar Naidu and other researchers from the University of Tennessee published a case study in 2008
that uses an outranking decision analysis method to select nanoparticle synthesis processes . Naidu, et al.,
evaluated the tradeoffs between three processes for silica nanoparticle synthesis: Sol-gel, a flame method
involving tetraethylorthosilicate (TEOS) precursor and a flame method involving hexamethyldisiloxane
(HMDSO) precursor. To facilitate the decision analysis, Naidu et al. (2008) used the Novel Approach to
Imprecise Assessment and Decision Environments (NAIADE) software package. The analysis involves
three steps: (a) pair wise comparison of alternatives, (b) aggregation of all comparison scores, and (c)
ranking of alternatives.
a. Pair wise comparisons of alternatives
The outranking method begins by making pair-wise comparisons between alternatives, one criterion at a
time. For a criterion j and a pair of alternatives /' and /', the NAIADE software uses six membership
functions to quantify the following comparisons:
• fi»(i,i')j (i much better than /')
• n>(i,i')j (i better than /')
• fia(i,i')j (i approximately equal to /')
• fi=(i,i')j (i very equal to /')
• fi<(i,i')j (i worse than /')
• /(«(/',/'), (/' much worse than /')
These comparisons are scaled from 0 to 1, where 0 is not true at all, 1 is very true, and 0.5 is unclear.
60
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Example - Outranking (continued)
b. Aggregation of comparison scores
The comparison scores for all criteria are aggregated into a single preference intensity index, u*(U')'
•(i,i')j-a
Where * stand for », >, ~, <, or «, and a is the threshold value below which values are not considered
. Determining the threshold (a) is important to the analysis and will likely involve input from experts
who are familiar with the given criteria.
In addition to calculating the preference intensity index, the NAIADE software calculates the entropy of
the intensity index, C*(/', /''), which indicates the variance in the indices that are above the threshold and
near 0.5 (maximum fuzziness) . An entropy value of 1 means that all criteria give an exact indication
(definitely credible or not credible) and an entropy value of 0 means that all criteria give an indication
biased by maximum fuziness (//.(/,/')=0.5).
c. Ranking of alternatives
The intensity indices and associated entropies are combined to rank the alternatives. The final ranking
is derived from two separate rankings, each one varying from 0 to 1. The first ranking, (|>+(i), indicates
the extent to which /' is better than all other alternatives, and the second ranking, (|>~(i), indicates the
extent to which /' is worse than all other alternatives:
^ (i, n) A Cv> (i, n) + M> (/, ri) A C, (/, n)}
(0 = -
(M>:> (/', ri) A Cy> (i, n) + u> (i, n) A C> (/', n)]
(0 = - - -i - -i -
4.3.2 Aggregating Weighted Impact Scores
As an alternative to outranking methods, the normalized and weighted impacts described
previously may be aggregated. Some aggregation methods are multi-attribute utility analysis
(MAUT) and analytical hierarchy process (AHP) and allow alternatives to be compared against
each other on a single scale. These methods are essentially compensatory (Kiker et al., 2005;
Linkov et al., 2007) (MAUT more so than AHP) and should be used with caution due to the non-
compensatory nature of sustainability. Further, they can be used to elucidate stakeholder values
and determine weights (Cohon, 2003).
While, both MAUT and AHP rely on stakeholder values to determine the weights, they differ in
the way that they derive weights for the criteria. Weighting in MAUT relies on utility functions,
while AHP utilizes pair-wise comparisons made by stakeholders. To elicit stakeholder values, the
AHP method asks stakeholders to make pair-wise comparisons between different criteria, which
61
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are then translated into a weighting scheme via matrix algebra techniques. Stochastic
Multiattribute Acceptability Analysis (SMAA) is another method for deriving weights from
stakeholder values. Unlike MAUT and AHP, SMAA includes information about uncertainties in
stakeholder values. As a result, SMAA can help to determine both a weighting scheme and the
sensitivity of results to uncertainties in stakeholder values (Seager and Linkov, 2008). Analytic
Network Process (ANP) is based on AHP, yet allows dependence between decision criteria. Once
the weights are determined, they are then multiplied by normalized impact scores (see Box).
Aggregating Weighted Impact Scores forNano Product X
In this example, an overall sustainability score is generated for three hypothetical synthetic processes by
summing the normalized and weighted scores for all criteria (lower is better). While Synthetic process #2
scores lower than process #3 on economic considerations and process #1 on social considerations, it has
the highest overall score. Note that these values are arbitrary, and for demonstration purposes only.
Selected Criteria Synthetic Process #1 Synthetic Process #2 Synthetic Process #3 1
Environmental
Energy use
Greenhouse gas
emissions
Potential aquatic toxicity
Economic
Consumer cost
Potential environmental
liabilities
Social
Job loss
Worker harm
Overall
0.8
0.25
0.31
0.24
0.53
0.35
0.18
1.34
0.89
0.45
2.67
1.59
0.36
0.25
0.98
1.03
0.46
0.57
0.7
0.46
0.24
3.32
1.11
0.2
0.45
0.46
1.11
0.53
0.58
0.64
0.28
0.36
2.86
Figure 4-4 is a plot of the hypothetical weighting schemes constructed in Canis et al. (2010). As
illustrated, the weighting systems are quite subjective and vary greatly based upon values and
priorities. For example, note that while costs are the primary concern for the manufacturer with
minor consideration of health risks, the environmentalist does not consider cost and assigned
equal weightings to health risks, energy consumption and material efficiency. When these
weights were applied in the MCDA, the order of the preferred options changed along with the
reasons for the desirability of the alternative. Consequently, ranking of the alternatives is
somewhat different for each scheme. The "Manufacturer", "End User" and "Regulator" all
preferred (ranked 1st) HIPCO, while the "Environmentalist" had a slightly higher preference for
the Laser alternative. The rank of the remaining alternatives varied greatly (Canis et al., 2010).
This exercise not only demonstrates the method but also highlights the fact that different
weighing schemes may result in quite different decisions. Accordingly, care must be taken when
evaluating alternatives and additional approaches (e.g., probabilistic method and/or sensitivity
analysis) may be needed to compensate for stakeholder uncertainty.
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100.00%
90.00%
80.00%
70-00°/°
60.00%
50.00%
40.00%
30.00%
20.00%
10.00%
0.00%
Health Risks
I Costs
Energy Consumption
I Material Efficiency
iLCIAScore
Figure 4-4. Comparison of Single Walled Carbon Nanotubes (SWCNT) Criteria Weightings
(adapted from Canis et al. 2010)
4.4 Uncertainty Analysis
As described in Section 3, there is a great deal of uncertainty involved in the assessment of
nanoproducts to include inherent uncertainty related to data quality and availability, costs and
impacts. While some uncertainties are nearly impossible to estimate (e.g., level of market
penetration), experts may be queried to get a qualitative sense of this variability (Seppala et al.,
2002). In an attempt to capture uncertainty, researchers involved in the SWCNT assessment
developed probabilistic estimations of the performance indicators (Canis et al., 2010). Data were
primarily gathered from literature surveys and used to develop triangular distributions for the
parameters. As in the case study, uncertainty is traditionally modeled by assigning probabilities
through expert testimony, theoretical modeling, fitting empirical data and/or simulation (Clemen
and Reilly, 2001; Keeney and Raiffa, 1976). While some level of uncertainty is present in any
assessment, it is of particular importance for new and emerging technologies due to the many
unknowns related to such issues as service level to the customer, upstream resource use, limited
exposure data, market penetration, cost data, systematic impacts on other economic sectors, etc.
As noted in Section 3, due to the multiple layers of uncertainty related to nanotechnology,
traditional approaches may be insufficient (Seager and Linkov, 2008). Hence, sensitivity and/or
scenario analysis may be more appropriate. Monte-carlo simulation is an approach not only for
investigating the impact of uncertainty, but also exploring various management scenarios. This
simulation approach is based upon altering variable values by selecting characteristic
distributions and computing results to determine the impact of changes in underlying variables.
Although sensitivity analysis provides insight on the impact of uncertainty, the range of possible
outcomes and aids in determining and implementing management decisions, much work is
needed on optimizing these methods (Basson, 1999).
4.5 Sensitivity Analysis and Scenario Analysis
Sensitivity analysis is a method of determining the effect changes in controllable variables have
on output response variables. In the context of DA, the aim of sensitivity analysis is to identify
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the input variables and values that may alter preferences for different alternatives. Accordingly, it
is crucial that the sources and types of uncertainties are identified and distinguished. While
probabilities may be defined to characterize some variables, others may require the use of random
sampling simulation and scenario analysis to get a sense of the range of uncertainty in the results.
Using this approach, the impact of uncertainty in the variable on the viability of a particular
alternative may be explored by varying key controllable variables.
Scenario Analysis is the strategic process of evaluating alternatives by considering possible future
activities and can be used to assess what will happen (predictive), can happen (explorative) or
how a specified target may be reached (normative) (Borjeson et al., 2006; Hojer et al., 2008).
This technique enhances decision making by affording the ability to assess the performance and
impact of alternatives given potential events and outcomes. For example, alternatives may be
evaluated based upon various levels of market penetration, resource availability, production
capacity or changing environmental regulation. Scenario analysis is used effectively in a number
of arenas to include military intelligence, as well as finance to explore changes in the economy
under several growth scenarios (e.g., rapid, decline or moderate). It is also used in long term
planning and emphasizes the importance of systems thinking when developing and evaluating
products, processes and systems. Because a system is typically comprised of many factors and
subsequent interactions, scenario analysis may highlight outcomes that are counterintuitive,
previously unknown or unexpected. The basic steps of scenario analysis include: determining
which factors will be considered and the scenarios to be evaluated for each factor, estimating the
outcomes and assigning the probabilities of various scenarios. Although estimating outcomes
may involve adapting knowledge of existing systems, it typically entails some type of modeling
or simulation activity. The resulting outcomes are compared for the alternatives across the
scenarios. While scenario analysis is a valuable planning tool and is used to explore impacts as a
result of what may happen, there are no assurances of what will happen; of course, this is true of
any forecasting tool. Resources related forecasting and scenario analysis include, among others,
Eriksson and Ritchey (Erikkson and Ritchey, 2002), Konsult and Nilsson (Konsult and Nilsson,
2005), Markham and Palocsay (Markham and Palocsay, 2006) , Eason et al (Eason et al., 2009),
Hojer et al. (2008), and Borjeson et al. (2006).
4.8
It is evident that the process of determining alternatives that satisfy the sustainability criteria will
require an iterative approach. As such, there is no illusion that ideal options will be determined on
first pass. Further, modifications due to technology enhancements, regulations, process
alterations, changing supply horizon or energy security issues may demand the need to adjust
viable options. Moreover, the results of the evaluation provide information on resources, stages or
processes that may be candidates for redesign or replacement. However, making improvements
with respect to one impact category of sustainability may adversely impact another category or
pillar. For example, consider the case where a non-renewable feedstock or material is replaced
with a renewable material that is processed in an upstream facility with a history of poor on-site
worker safety. Although this substitution may improve the environmental sustainability of the
product, it may have a negative impact on its social sustainability. Therefore, alternative
approaches developed to mitigate impacts must be assessed according to the sustainability criteria
and evaluated. While determining the impact of the substitution outlined above may require a full
re-assessment, if replacing one material with the other does not affect other aspects of the product
system, it may be appropriate to simply assess differences in impacts between the two materials.
Much like an adaptive management approach, developing more sustainable alternatives may
occur several times over the course of a product's lifetime and the number of times this process is
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repeated depends on the need for and feasibility of developing alternatives. It is important to note
that DA approaches are meant to facilitate decisions, not replace decision makers. As such, after
conducting a decision analysis, it is advisable to discuss the results with stakeholders before
selecting and implementing an approach.
5. Conclusions
By focusing on sustainability, product researchers, developers, and manufacturers can help ensure
that as nanoproducts advance, they realize their potential benefits to society without jeopardizing
the well-being of humans or the environment, in this generation and beyond. There are many
unknowns surrounding nanotechnologies and nanoproducts, both in terms of performance and
impacts on the environment, economy, and society. The preliminary framework presented in this
guidance should aid in better organizing and understanding the known life-cycle impacts, as well
as help product developers prioritize new research to better understand the unknowns. This
document is intended to offer a starting point for assessing the sustainability of nanoproducts and
provides a summary of existing methods for assessing various aspects of sustainability. Further, it
highlights the critical elements needed for supporting sustainability based decision making.
Feedback gathered from this report will be used for enhancement of the work, clarification of the
approach and prioritization of future research. Moreover, given that the fields of nanotechnology
and life cycle approaches are changing rapidly, this document will be reviewed and updated as
additional information becomes available.
6. Acknowledgements
Our thanks go to Shanika Amarakoon and Brian Segal of Abt Associates who provided us with
the initial material for this document. The team would also like to thank Kathy Hart (Office of
Chemical Safety and Pollution Prevention: OCSPP), Jim Alwood (OCSPP), Kristan Markey
(OCSPP), Tom Seager (Arizona State University), Igor Linkhov (US Army Corps of Engineers),
Mike Davis (National Center for Environmental Assessment) and his post docs: Patricia Gillespie
and Christy Powers) and Alessandra Zamagni (Italian National Agency for New Technologies,
Energy and the Environment) for their valuable comments, suggestions and insight.
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2003 Sustainable development in dynamic world: Transforming institutions, growth and
quality of life The World Bank Washington DC, USA.
Aaltonen, K. 2011. Project stakeholder analysis as an environmental interpretation
process. Int. J. Proj. Mgmt. 29, 165-183.
AccountAbility 2008 AA 1000 Assurance Standard 2008, pp. 1-28, AccountAbility,
Washington D.C.
Alan, B.D., Ken, C.H., Anne, H.P. and Michael, A.T. 2003 A human dimensions
framework: Guidelines for conducting social assessments, pp. 1-83, US
Department of Agriculture, Asheville, NC, ISA.
Anex, R.P. and Focht, W. 2002. Public transportation in life cycle assessment and risk
assessment: a shared need. Risk. Anal. 22(5), 861-877.
Arnold, G.L., Abnbar, A.D., Barling, J. and Lyons, T.W. 2004. Molybdenum isotope
evidence for widespread anoxia in mid proterozic oceans. Science 304, 87-90.
Azapagic, A. and Clift, R. 1998. Linear programming as a tool for life cycle assessment.
The International Journal of Life Cycle Assessment 3(6), 305-316.
Azapagic, A., Millington, A. and Collett, A. 2006. A methodology for integrating
sustainability considerations into process design. Chemical Engineering Research
and Design 84(6), 439-452.
Azapagic, A. and Perdan, S. 2005. An integrated sustainability decision-support
framework: Methods and tools for problem analysis, Part II. International Journal
of Sustainable Development and World Ecology 12(2), 112-131.
Bailey, J.A., Amyotte, P. and Khan, F.I. 2010. Agricultural application of life cycle
iNdeX(LinX) for effective decision making. Journal of Cleaner Production 18(16-
17), 1703-1713.
Baker, D., Bridges, D., Hunter, R., Johnson, G., Krupa, J., Murphy, J. and Sorenson, K.
2001 Guide book to decision making methods, US Department of Energy
Washington D.C.
BASF. What is the SEEBALANCE® ? 2011 [cited 2011 April 18th ]; Available from:
http://www.basf.com/group/corporate/en/sustainability/eco-efficiency-
analysis/seebalance.
Basson, L. (1999) Decision making for effective environmental management: Multiple
criteria decision analysis and management of uncertainty University of Sydney,
Sydney, Australia.
Bauer, C., Buchgeister, J., R.Hishier, Poganietz, W.R., Schebek, L. and Warsen, J. 2008.
Towards a framework for life cycle thinking in the assessment of nanotechnology.
Journal of Cleaner Production 16, 910-926.
Baumann, H. and Tillman, A.M. 2004. The hitch hiker's guide to LCA, Studentlitteratur,
Lund, Sweden.
Bell, T.E. Understanding risk assessment of nanotechnology. 2007 [cited 2011 April
18th]; Available from: www.nano.gov/Understanding_Risk_Assessment.pdf
Benoit, C. andNorris, G. History of the project: The social hotspots database. 2007 [cited
2011 May 4th]; Available from: http://www.socialhotspot.org/content/history-
project.
Berkel, R.V. 2000 The sustainable development challenge for technology: will it work in
time?, pp. 1-17, p2pays.org, Perth, Australia.
66
-------
Bhushan, B. (ed) 2007. Handbook of nanotechnology, Springer-Verlag, New York
Borjeson, L., Hqjer, M., Dreborg, K.-H., Ekvall, T. and Finnveden, G. 2006. Scenario
types and scenario techniques: Towards user's guide to scenarios. Futures 38(7),
723-739.
Bryson, J.M. 2004. What to do when stakeholders matter Public Management Review
6(1), 21-53.
BSI2008 Guide to PAS 2050: How to assess the carbon footprint of goods and services,
p. 58, British Standards Institute, Surrey, UK.
CALCAS 2008 D10 SWOT analysis of concepts, methods and models potentially
supporting life cycle analysis 037075. Schepelmann, P., Ritthoff, M., Santman, P.,
Jeswani, H. and Azapagic, A. (eds), Wuppertal Institute for Climate,
Environment, Energy, Manchester, UK.
Canis, L., Linkov, I. and Seager, T.P. 2010. Application of stochastic multiattribute
analysis to assessment of single walled carbon nanotube synthesis process. Env.
Sci. Technol. 44(22), 8704-8711.
Chen, S.J., Hwang, C.L. and Hwang, F.P. 1992. Fuzzy multiple attribute decision
making: methods and applications, Springer-Verlag, New York.
Chu, K., Lei, W., Zhang, X., Di, Y., Chen, J. and Yang, X. 2006 Study of normal gate
CNT-FED using HOP glass, pp. 437-438, IEEE, USA.
Clemen, R.T. 1996. Making hard decisions: An introduction to decision analysis,
Duxbury Press, Pacific Grove, CA, USA.
Clemen, R.T. and Reilly, T. 2001. Making hard decisions with decision tools suite,
Duxbury Press, Pacific Grove, CA, USA.
CMU. Economic input-output life cycle assessment (EIO-LCA), creating a hybrid EIO-
LCA and process-based LCA. 2008a [cited 2011 April 18th ]; Available from:
http://www.eiolca.net/LCAexperts/hybrid-lca-models.html.
CMU. EIO-LCA: Free, fast, easy life cycle assessment. 2008b [cited 2011 April 18th ];
Available from: http://www.eiolca.net/.
Cohon, J.L. 2003. Multi objective programming and planning, Academic Press, New
York, USA.
CSRR-QS. Corporate sustainability and responsible research - Quality standard for SRI
research. 2010 [cited 2011 April 18th ]; Available from: http://www.csrr-qs.org/.
Cuppen, E., Breukers, S., Hisschemoller, M. and Bergsma, E. 2010. Q methodology to
select participants for a stakeholder dialogue on energy options from biomass in
the Netherlands. Ecological Economics 69, 579-591.
Davidson and Julie, L. 2001. Taking sides: Clashing views on controversial
environmental issues Goldfarb, T.D. (ed), pp. 294-296, Dushkin/McGraw Hill,
Hightstown, NJ.
Davies, J.C. 2009 Oversight of next generation nanotechnology pp. 1-48, Woodrow
Wilson International Center for Scholars, Washington DC, USA.
Dreyer, L.C. and Hauschild, M.Z. 2010. Characterization of social impacts in LCA. Part
1: Development of indicators for labour rights The International Journal of Life
Cycle Assessment 15(3), 247-259.
Dreyer, L.C., Hauschild, M.Z. and Schierbeck, J. 2006. A framework for social life cycle
impact assessment The International Journal of Life Cycle Assessment 11(2), 88-
97.
67
-------
Eason, T., Hans, C. and Yaw, O. 2009. A systematic approach to assessing the
sustainability of the renewable energy standard (RES) unhder the proposed
american renewable energy act (H.R. 890) International Journal of Global Energy
32(1-2), 139-159.
ED-DuPont 2007. Nano Risk Framework, Environmental Defense-DuPont Nano
Partnership.
EPA-SPC 2007 Nanotechnology white paper, pp. 1-136, US Environmental Protection
Agency, Washington DC, USA.
EPA 2006 Life cycle assessment: Principles and practice EPA/600/R-06/060, pp. 1-88,
Scientific Applications International Corporation, Reston, VA, USA.
EPA. Risk assessment: Basic information. 2010 [cited 2011 April 18th]; Available from:
http://www.epa.gov/risk/basicinformati on.htm#arisk.
Erikkson, T. and Ritchey, T. 2002 Developing scenario laboratories with computer aided
morphological analysis pp. 1-8, London, UK.
Fiksel, J. 2006. A framework for sustainable materials management. JOM Journal of the
Minerals, Metals and Materials Society 58(8), 15-22.
Fink and Lee, R. 2005 Bead blast activation of carbon nanotube cathode. Office, U.S.P.
(ed), pp. 1-10, Nano Proprietery Inc USA.
Freeman, R.E. 1984. Strategic management: A stakeholder approach Cambridge
University Press, Cambridge, UK.
Gooday, A.J., Jorissen, F., Levin, L.A., Middelburg, J.J., Naqvi, S.W.A., Rabalais, N.N.,
Scranton, M. and Zhang, J. 2009. Historical records of coastal eutrophication-
induced hypoxia Biogeosciences Discuss 6, 2567-2568.
GRI2006 Sustainability reporting guidelines, pp. 1-45, Global Reporting Initiative,
Amsterdam, The Netherlands.
Guitoni, A. and Martel, J.M. 1998. Tentative guidelines to help choosing an appropriate
MCDA method. European Journal of Operational Research 109(2), 501-521.
Halog, A. and Manik, Y. 2011. Advancing integrated systems modelling framework for
life cycle sustainability assessment. Sustainability 3(2), 466-499.
Hansen, H.O., Gerloff, G.C. and Skoog, F. 1954. Cobalt as essential element for blue
green algae. Physiologia Plantarum 7, 665-675.
Hart, K. Lithium ion batteries and nanotechnology partnership. 2009 [cited 2011 May
4th]; Available from: http://www.epa.gov/dfe/pubs/projects/lbnp/index.htm.
Hauschild, M.Z., Dreyer, L.C. and Jorgensen, A. 2008. Assessing social impacts in a life
cycle perspective - lessons learned. CIRP Annals - Manufacturing Technology 57,
21-24.
Helland, A., Scheringer, M., Siegrist, M., Kastenholz, M., Wiek, A. and Scholz, R.W.
2007. Risk assessment of engineered nanomaterials: A survey of industrial
approaches. Environ Sci Tech 42(2), 640-646.
Hirschberg, S., Bauer, C., Burgherr, P., Dones, R., Schenler, W., Bachmann, T. and
Carrera, D.G. 2007 Environmental, economic and social criteria and indicators for
sustainability assessment of energy technologies 502687/D3.1-RS 2b, pp. 1-31,
Paul Scherrer Institut, Stuttgart, Germany.
Hqjer, M., Ahlroth, S., Dreborg, K.-H., Ekvall, T., Finnveden, G., Hjelm, O.,
Hochschorner, E., Nilsson, M. and Palm, V. 2008. Scenarios in selected tools for
environmental system analysis Journal of Cleaner Production 16(18), 1958-1970.
68
-------
Hopton, M.E., Cabezas, H., Campbell, D.E., Eason, T., Garmestani, A.S., Heberling,
M.T., Karunanithi, A.T., White, D. and Zanowick, M.A. 2011 A multidisciplinary
approach to regional sustainability pp. 1-227, US Environmental Protection
Agency, Washington DC, USA.
Huang, IB., Keisler, J. and Linkov, I. 2011. Multi-criteria decision analysis in
environmental sciences: Ten years of applications and trends Science of Total
Environment 409(19), 3578-3594.
Hunkeler, D., Lichtenvort, K. and Rebitzer, G. (eds) 2008. Environmental Life cycle
costing, CRC Press, Boca Raton, FL.
ISO 2006 ISO 14040: Environmental management - life cycle assessment principles and
framework pp. 1-91, International Standards Organization, Paris.
ISO 2009 ISO 26000: Guidance on social responsibility, pp. 1-91, International Standards
Organization, Geneva.
ISO 2010 Nanotechnologies-Methodology for classification and categorization of
nanomaterials p. 25, International Organization for Standardization, Geneva,
Switzerland.
Jorgensen, A., Le Bocq, A., Nazarkina, L. and Hauschild, M. 2008. Methodologies for
social life cycle assessment. The International Journal of Life Cycle Assessment
13(2), 96-103.
Journet, C., Maser, W.K., Bernier, P., Loiseau, A., chapelle, M.L.d.l., Lefrant, S.,
Deniard, P., Lee, R. and Fischer, I.E. 1997. Large scale production of single-
walled carbon nanotubes by electric arc discharge technique. Letters to Nature
388, 756-757.
JRC 2010. International reference life cycle data system handbook (ILCD): General
guidance for life cycle assessment, Luxembourg Publications, Office of European
Union Ispra (VA) Italy
Kangas, A., Kangas, J. and Pykalainen, J. 2001. Outranking methods as tools in strategic
natural resources planning. Silva Fennica 35(2), 215-227.
Kauffman, YJ. and Fraser, R.S. 1997. The effect of smoke particles on clouds and
climate forcing. Science 277, 1636-1639.
Keeney, R. and Raiffa, H. 1976. Decisions with multiple objectives: Preferences and
value tradeoffs John Wiley & Sons New York
Khanna, V., Bakshi, B.R. and Lee, LJ. 2007 Life cycle energy analysis and
environmental life cycle assessment of carbon nanofibers production pp. 128-133,
IEEE, Orlando, FL, USA.
Kiker, G.A., Bridges, T.S., Varghese, A., Seager, P.T. and Linkov, I. 2005. Application
of multicriteria decision analysis in environmental decision making. Integr
Environ Assess Manag. 1(2), 95-108.
Klimberg, R.K. and Miori, V. 2010. Back in business. ORMS Today 37(5), 22-27.
Klopffer, W. 2008. State-of-the-art in life cycle sustainability assessmen (LSCA). The
International Journal of Life Cycle Assessment 13(2), 89-95.
Klopffer, W., Curran, M.A., Frankl, P., Heijungs, R., Kohler, A. and Olsen, S.I. 2007
Nanotechnology and life cycle assessment: A systems approach, pp. 1-37,
Woodrow Wilson International Center for Scholars Wasgington DC, USA.
69
-------
Kohler, A.R., C.Som, Helland, A. and Gottschalk, F. 2008. Studying the potential release
of carbon nanotubes throughout the application life cycle. Journal of Cleaner
Production 16, 927-937.
Konsult, B. andNilsson, J.B. 2005 Scenario analysis including SWOT analysis: Abaltic
gateway report, pp. 1-107, Tetra Plan A/S Baltic Gateway.
Kordas, K., Mustonen, T., Toth, G., Jantunen, H., Lajunen, M., Soldano, C., Talapatra,
S., Kar, S., Vajtai, R. and Ajayan, P. 2006. InkJet printing of electrically
conductive patterns of carbon nanotubes. Small 2, 1021-1025.
Kushnir, D. and Sanden, B.A. 2008. Energy requirements of carbon nanoparticle
production. Journal of Industrial Ecology 12(3), 360-375.
Linkov, I, Satterstrom, F.K., Kiker, G.A., Batchelor, C., Bridges, T.S. and Ferguson, E.
2006. From comparative risk assessment to multi-criteria decision analysis and
adaptive managment: Recent developments and applications. Environment
International 32(8), 1072-1093.
Linkov, I, Satterstrom, F.K., Steevens, J., Ferguson, E. and Pleus, R.C. 2007. Multi
criteria decision analysis and environmental risk assessment for nanomaterials
Journal of Nanoparticle Research 9(4), 543-554.
Linkov, I. and Seager, P.T. 2011. Coupling multi-criteria decision analysis, life cycle
assessment, and risk assessment for emerging threats. Env. Sci. Technol. 45(12),
5068-5074.
Linkov, I, Steevens, J., Chappell, M., Tervonen, T., Figueira, J.R. and Merad, M. 2009.
Nanomaterials: Risks and Benefits. Linkov, I. and Steveens, J. (eds), pp. 179-191,
Springer Science, Faro, Portugal.
Linkov, I, Varghese, A., Jamil, S., Seager, P.T., Kiker, G.A. and Bridges, T. 2004.
Comparative Risk Assessment and Environmental Decision Making Linkov, I.
and Ramadan, A. (eds), pp. 15-54, Kluwer Press, Amsterdam.
MacLean, R. 2009. The road to (environmental) hell is paved with good intentions.
Environmental Quality Management 19(2), 93-99.
Markham, IS. and Palocsay, S.W. 2006. Scenario analysis in spreadsheets with Excel's
scenario tool. INFORMS Trans. Ed. 6(2), 23-31.
McDaniels, T.L., Gregory, R.S. and Fields, D. 1999. Democratizing risk management:
Successful public involvement in local water management decisions. Risk
Analysis 19(3), 497-510.
Merkhofer, M.W. 1999. Tools to aid Environmental Decision Making. Dale, V.H. and
English, M.R. (eds), pp. 231-281, Springer New York
Mitchell, R.K., Agle, B.R. and Wood, D.J. 1997. Toward a theory of stakeholder
identification and salience: Defining the principle of who and what really counts.
Academy of Management Review 22(4), 853-886.
Mueller, N.C. and Nowack, B. 2008. Exposure modelling of engineered nanoparticles in
the environment Environ Sci Tech 42(12), 4447-4453.
Naidu, S., Sawhney, R. and Li, X. 2008a. A methodology for evaluation and selection of
nanoparticle manufacturing processes based on sustainability metrics. Environ Sci
Tech 42(17), 6697-6702.
Naidu, S., Sawhney, R. and Li, X.P. 2008b. A methodology for evaluation and selection
of nanoparticle manufacturing processes based on sustainability metrics.
Environmental Science & Technology 42(17), 6697-6702.
70
-------
NNI2010 Risk management methods, & ethical, legal, and societal implications of
nanotechnology report of the national nanotechnology initiative workshop. 2011.
Heeter, L. (ed), pp. 1-76, National Science and Technology Council Arlington,
VA.
NNI. Goal four objectives. 2011 [cited 2011 Sep 6th ]; Available from:
http://www.nano.gov/goalfourobjectives
Norris, G.A. 2006. Social impacts in product life cycles: Towards life cycle attribute
assessment. The International Journal of Life Cycle Assessment 11(1), 97-104.
Norris, G.A. and Marshall, H.E. 1995 Multiattribute decision analysis method for
evaluating buildings and building systems pp. 1-82, NIST, Gaithersburg, MD,
USA.
OECD 2005 Working group on waste prevention and recycling, OECD, Seoul, South
Korea.
OECD. List of manufactured nanomaterials and list of endpoints for phase one of the
OECD testing programme Series on the Safety of Manufactured Nanomaterials
Number 6 2008 [cited 2011 April 18th ]; Available from:
http://applil.oecd.org/olis/2008doc.nsf/linkto/env-jm-mono(2008)13.
Olapiriyakul, S. and Caudill, RJ. 2008 A framework for risk management and end-of-life
(EOL) analysis for nanotechnology products; A case study of lithium ion
batteries, pp. 1-8, IEEE, San Francisco, CA, USA.
ONGO 1987 Report of the world commission on environment and development, United
Nations Oxford.
Ostertag, K. and Husing, B. 2008. Identification of starting points for exposure
assessment in the post use phase of nanomaterial containing products Journal of
Cleaner Production 16(8-9), 938-948.
Palmberg, C., Dernis, H. and Miguet, C. 2009 Nanotechnology: An overview based on
indicators and statistics, pp. 1-112, OECD, Paris.
Park, J.Y. (2009) Occupational exposure assessment for nanoparticles University of
Minnesota, Minnesota.
Parsons, S. and Wooldridge, M. 2002. Game theory and decision theory in multi-agent
systems. Journal of Autonomous Agents and Multi-Agent Systems 5(3), 243-254.
Petersen, E.J., Pinto, R.A., Landrum, P.P. and Jr, W.J.W. 2009. Influence of carbon
nanotubes on pyrene bioaccumulation from contaminated soils by earthworms.
Environ. Sci. Tech 43, 4181-4187.
Peterson, M. 2009. An introduction to decision theory, Cambridge University Press,
Cambridge, UK.
Plata, D.L., Hart, A.J., Reddy, C.M. and Gschwend, P.M. 2009. Early evaluation
potential environmental impacts of carbon nanotube synthesis by chemical vapor
deposition. Environ. Sci. Technol 43, 8367-8373.
Reed, M.S., Graves, A., Dandy, N., Posthumus, H., Hubacek, K., Morris, J., Prell, C.,
Quinn, C.H. and Stringer, L.C. 2009. Who's in and why? A typology of
stakeholder analysis methods for natural resource management. J. Environmental
Management 90, 1933-1949.
Roco, M.C. Nanoscale based emerging science and engineering. 2009 [cited 2011 April
18th ]; Available from: http://www.nanoinstitute.utah.edu/static-
71
-------
content/nanoinstitute/NNI_09-
1015_Roco@NanoUtah_Emerging%20SE_70sl.pdf
Rosenbaum, R.K., Bachmann, T.M., Gold, L.S., Huijbregts, M.A.J., Jolliet, O., Juraske,
R., Kohler, A., Larsen, H.F., MacLeod, M., Margni, M., McKone, I.E., Payet, J.,
Schuhmacher, M., van de Meent, D. and Hauschild, M.Z. 2008. USEtox - The
UNEP-SETAC toxicity model: recommended characterization factors for human
toxicity and freshwater ecotoxicity in life cycle assessment International Journal
of Life Cycle Assessment 13(7), 532-546.
Saaty, T.L. 1988. Decision making for leaders: The analytical hierarchy process for
decisions in a complex world, RWS Publications, Pittsburgh, PA, USA.
SAL Social Accountability International. 2008 [cited 2011 April 18th]; Available from:
http ://www. sa-intl. org/.
Saling, P., Kicherer, A., Dittrich-Kramer, B., Wittlinger, R., Zombik, W., Schmidt, I,
Schott, W. and S., S. 2002. Eco-efficiency analysis by BASF: The method.
International Journal of Life Cycle Assessment 7(4), 203-218.
Seager, T.P. and Linkov, I. 2008. Coupling multcriteria decision analysis and life cycle
assessment for nanomaterials. Journal of Industrial Ecology 12(3), 282-285.
Sengul, H., Theis, T.L. and Ghosh, S. 2008. Towards sustainable nanoproducts. Journal
of Industrial Ecology 12(3), 329-359.
Seppala, J. 1999. LCA Documents. Kloepffer, W. and Hutzinger, O. (eds), Eco-Informa
Press, Bayreuth, Germany.
Seppala, J., Basson, L. and Norris, G. 2002. Decision analysis frameworks for life cycle
impact assessment. J. Ind. Ecol. 5, 45-68.
SET AC (ed) 1992. A conceptual framework for life cycle impact assessment SET AC
Foundation for Environmental Education Washington DC, USA.
SET AC 2009. Environmental life cycle costing: A code of practice, SET AC Press,
Brussels.
Shatkin, J.A. 2008. Informing environmental decision making by combining life cycle
assessment and risk analysis. Journal of Industrial Ecology 12(3), 278-281.
Shea, C.M. 2005. Future management research directions in nanotechnology: A case
study. J. Eng. Technol. Manage. 22, 185-200.
Sikdar, S.K. and Murray, D.J. 2010. Energy and water sustainability: What do they mean
and can we know when we achieved them? Environmental Research, Engineering
and Management 2(52), 5-13.
Singh, A., Lou, H.H., Pike, R.W., Agboola, A.E., Li, X., Hopper, J.R. and Yaws, C.L.
2008. Environmental impact assessment for potential continuous processes for the
production of carbon nanotubes. American Journal of Environmental Sciences
4(5), 522-534.
Sinha, N., Ma, J. and Yeow, J.T.W. 2006. Carbon nanotube based sensors Journal of
Nanoscience and Nanotechnology 6, 573-590.
Smith, H. What innovation is? 2005 [cited 2011 May 4th ]; Available from:
http://www.innovationtools.com/pdf/innovati on_update_2005.pdf.
Stewart, T.J. 1992. A critical survey on the status of multiple criteria decision making
theory and practice. OMEGA International Journal of Management Science 20,
569-586.
72
-------
Swarr, T.E. 2009. Societal life cycle assessment - could you repeat this question? The
International Journal of Life Cycle Assessment 14(4), 285-289.
Tervonen, T., Linkov, I, Figueira, J., Steevens, J., Chappell, M. and Merad, M. 2009.
Risk based classification system on nanomaterials Journal of Nanoparticle
Research 11 (4), 757-766.
UNEP 2009a Guidelines for social life cycle assessment of products, pp. 1-104,
UNEP/SETAC, Quebec, Canada.
UNEP 2009b Guidelines for social life cycle assessment of products, pp. 1-104, UNEP,
Quebec, Canada.
USEPA 1976 Vapor phase organic pollutants: Volatile hydrocarbons and oxidation
products EPA-600/1-75-005, pp. 1-670, United States Environmental Protection
Agency, Washington DC.
USEPA 1977 Airborne particles: Medical and biological effects of environmental
pollutants EPA-600/1-77-053, pp. 1-558, United States Environmental Protection
Agency, Washington DC.
Vanclay, F. 2003. International principles for social impact assessment Impact
assessment and project appraisal 21(1), 5-11.
Walsh, S., Balbus, J.M., Denison, R. and Florini, K. 2008. Nanotechnology: getting it
right the first time. Journal of Cleaner Production 16(8-9), 1018-1020.
Walsh, S. and Medley, T. 2007 Environmental defense- DuPont nano partnership, pp. 1-
87, DuPont, Wilmington, DE, USA.
Weidema, B.P. 2006. The integration of economic and social aspects in life cycle
assessment The International Journal of Life Cycle Assessment 11(1), 89-96.
White, A.L., Savage, D.E., Brody, J., Cavander, D. and Lach, L. 1995 Environmental
cost accounting for capital budgeting: A bench mark survey of management
accountants, p. 70, Tellus Institute Arlington, VA, USA.
Wiedema, B.P. Input-output databases for life cycle assessment 2.0 LCA consultants.
2010 [cited 2011 April 18th ]; Available from: http://www.lca-net.com/io-
databases/.
Wiesner, M.R., Lowry, G.V., Alvarez, P., Dionysiou, D. and Biswas, P. 2006. Assessing
the risks of manufactured nanomaterials Environ Sci Tech 40(14), 4336-4345.
Wolfslehner, B. (2008) Potentials and limitation of multi criteria analysis method in
assessing sustainable forest management, Institue of Siviculture, University of
Natural and Applied Life Sciences, Vienna.
WRI. The greenhouse gas protocol initiative. 2010 [cited 2011 April 18th ]; Available
from: http://www.ghgprotocol.org/.
Yang, K., Zhu, L. and Xing, B. 2006. Adsorption of polycyclic aromatic hydrocarbons by
carbon nanomaterials. Env. Sci. Technol. 40(6), 1855-1861.
Yoon, K.P. and Hwang, C.L. (eds) 1995. Multiple attribute decision making: An
introduction.
Young, M. What is stakeholder analysis and why should you do it?" Principal consultant
with transformed. 2008 [cited 2011 April 18th ]; Available from:
http://www.docstoc.com/docs/2252199/What-is-stakeholder-analysis-and-why-
should-you-do-it-What-is-a.
Zamagni, A., Buttol, P., Buonamici, R., Masoni, P., Guinee, J.B., Huppes, G., Heijungs,
R., van der Voet, E., Ekvall, T. and Rydberg, T. 2009 CALCAS: D20 blue paper
73
-------
on life cycle sustainability analysis, Institute of Environmental Sciences, Lieden
University, Leiden, The Netherlands.
Zhang, Y., Baral, A. and Bakshi, B. 2010a. Accounting for Ecosystem Services in Life
Cycle Assessment, Part II: Toward an Ecologically Based LCA. Environmental
Science and Technology 44, 2624-2631.
Zhang, Y., Baral, A. and Bakshi, B.R. 2010b. Accounting for ecosystem services in life
cycle assessment, Part II: Toward an ecologically based LCA. Environ Sci Tech
44(7), 2624-2631.
Zhang, Y., Singh, S. and Bakshi, B.R. 2010c. Accounting for ecosystem services in life
cycle assessment, Part I: A critical review. Environ Sci Tech 44(7), 2232-2242.
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Appendix: List of Additional Resources
Government Organizations
• EPA Life Cycle Assessment Research: http://www.epa.gov/nrmrl/lcaccess/
• ORD's Nanotechnology LCA website: http://epa.gov/nanoscience/quickfinder/lifecycle.htm
• EPA Lean Home: http://www.epa.gov/lean/
• ORD Sustainable Technologies: http://www.epa.gov/nrmrl/std/
• ORD's Nanotechnology website: http://epa.gov/nanoscience/
• EPA Sustainable Futures: http://www.epa.gov/oppt/sf/
Public-Private Partnerships
• Woodrow Wilson Center - Nano and LCA
http ://www. nanotechproj ect. org/file_download/files/NanoLC A_3.07 .pdf
• PEN - The Project on Emerging Nanotechnologies (Woodrow Wilson Center)
http ://www. nanotechproj ect. org/publications/
• Life Cycle Initiative: http://jpl.estis.net/sites/lcinit/default.asp?site=lcinit
• CALCAS Co-ordination Action for innovation in Life-Cycle Analysis for Sustainability
http://www.calcasproject.net
Non-Profit and Professional Organizations
• International Society for Industrial Ecology: http://www.is4ie.org/
• AIChE Sustainable Engineering Forum:
http://www.aiche.org/DivisionsForums/ViewAll/SEF.aspx
• SET AC site on LCA: http://www.setac.org/node/32
• American Center for Life Cycle Assessment: http://www.lcacenter.org/
• Athena Institute: http://www.athenasmi.org/index.html
• Global Reporting Initiative: http://www.globalreporting.org
• Ceres : http://www.ceres.org/
• Wuppertal Institute: http://www.wupperinst.org/en
Industry Organization
• Center for Environmental Assessment of Products and Materials
http://www.cpm.chalmers.se/links.htm
• Nanotechnologies Industry Association: http://www.nanotechia.org/
Academic Institutions
• The Center for Environmental Implications of Nanotechnology (CEIN)
http://cein.cnsi.ucla.edu/pages/
• Carnegie Mellon Green Design publications
http://www.ce.cmu.edu/GreenDesign/publications/index.html
• Ohio State Center for Resilience: http://resilience.eng.ohio-state.edu/CFR-site/tools.htm
• Arizona State Center for Nanotechnology in Society: http://cns.asu.edu/
• International Council on Nano technology: http://icon.rice.edu/
Magazines and Journals
• Nanowerk Magazine: http://www.nanowerk.com/
• Nanotechnology Now: http://www.nanotech-now.com/
• Nano Magazine: http://www.nanomagazine.co.uk/
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