Nanotechnology
Nanomaterials Are Widely Used in Commerce, but EPA Faces Challenges in Regulating Risk Gao ID: GAO-10-549 May 25, 2010Nanotechnology involves the ability to control matter at the scale of a nanometer--one billionth of a meter. The world market for products that contain nanomaterials is expected to reach $2.6 trillion by 2015. In this context, GAO (1) identified examples of current and potential uses of nanomaterials, (2) determined what is known about the potential human health and environmental risks from nanomaterials, (3) assessed actions EPA has taken to better understand and regulate the risks posed by nanomaterials as well as its authorities to do so, and (4) identified approaches that other selected national authorities and actions U.S. states have taken to address the potential risks associated with nanomaterials. GAO analyzed selected laws and regulations, reviewed information on EPA's Nanoscale Materials Stewardship Program, and consulted with EPA officials and legal experts to obtain their perspectives on EPA's authorities to regulate nanomaterials.
Companies around the world are currently harnessing the properties of nanomaterials for use in products across a number of sectors and are expected to continue to find new uses for these materials. GAO identified a variety of products that currently incorporate nanomaterials already available in commerce across the following eight sectors: automotive; defense and aerospace; electronics and computers; energy and environment; food and agriculture; housing and construction; medical and pharmaceutical; and personal care, cosmetics and other consumer products. Within each of these sectors, GAO also identified a wide variety of other uses that are currently under development and are expected to be available in the future. The extent to which nanomaterials present a risk to human health and the environment depends on a combination of the toxicity of specific nanomaterials and the route and level of exposure to these materials. Although the body of research related to nanomaterials is growing, the current understanding of the risks posed by these materials is limited. This is because the manner in which some studies have been conducted does not allow for valid comparisons with newer studies or because there has been a greater focus on certain nanomaterials and not others. Moreover, the ability to conduct necessary research on the toxicity and risks of nanomaterials may be further hampered by the lack of tools to conduct such studies and the lack of models to predict the characteristics of nanomaterials. EPA has undertaken a multipronged approach to understanding and regulating the risks of nanomaterials, including conducting research and implementing a voluntary data collection program. Furthermore, under its existing statutory framework, EPA has regulated some nanomaterials but not others. Although EPA is planning to issue additional regulations later this year, these changes have not yet gone into effect and products may be entering the market without EPA review of all available information on their potential risk. Moreover, EPA faces challenges in effectively regulating nanomaterials that may be released in air, water, and waste because it lacks the technology to monitor and characterize these materials or the statutes include volume based regulatory thresholds that may be too high for effectively regulating the production and disposal of nanomaterials. Like the United States, Australia, Canada, the United Kingdom, and the European Union have begun collecting data to understand the potential risks associated with nanomaterials and are reviewing their legislative authorities to determine the need for modifications. Australia and the United Kingdom have undertaken a voluntary data collection approach whereas Canada plans to require companies to submit certain types of information. Some U.S. states, like California, have also begun to address the potential risks from nanomaterials by, for example, collecting information from manufacturers on a limited number of nanomaterials in use in those states and making some of this information publicly available.
RecommendationsOur recommendations from this work are listed below with a Contact for more information. Status will change from "In process" to "Open," "Closed - implemented," or "Closed - not implemented" based on our follow up work.
Director: Anu K. Mittal Team: Government Accountability Office: Natural Resources and Environment Phone: (202) 512-9846GAO-10-549, Nanotechnology: Nanomaterials Are Widely Used in Commerce, but EPA Faces Challenges in Regulating Risk
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Report to the Chairman, Committee on Environment and Public Works,
U.S. Senate:
United States Government Accountability Office:
GAO:
May 2010:
Nanotechnology:
Nanomaterials Are Widely Used in Commerce, but EPA Faces Challenges in
Regulating Risk:
GAO-10-549:
GAO Highlights:
Highlights of GAO-10-549, a report to Chairman, Committee on
Environment and Public Works, U.S. Senate.
Why GAO Did This Study:
Nanotechnology involves the ability to control matter at the scale of
a nanometer”one billionth of a meter. The world market for products
that contain nanomaterials is expected to reach $2.6 trillion by 2015.
In this context, GAO (1) identified examples of current and potential
uses of nanomaterials, (2) determined what is known about the
potential human health and environmental risks from nanomaterials, (3)
assessed actions EPA has taken to better understand and regulate the
risks posed by nanomaterials as well as its authorities to do so, and
(4) identified approaches that other selected national authorities and
actions U.S. states have taken to address the potential risks
associated with nanomaterials. GAO analyzed selected laws and
regulations, reviewed information on EPA‘s Nanoscale Materials
Stewardship Program, and consulted with EPA officials and legal
experts to obtain their perspectives on EPA‘s authorities to regulate
nanomaterials.
What GAO Found:
Companies around the world are currently harnessing the properties of
nanomaterials for use in products across a number of sectors and are
expected to continue to find new uses for these materials. GAO
identified a variety of products that currently incorporate
nanomaterials already available in commerce across the following eight
sectors: automotive; defense and aerospace; electronics and computers;
energy and environment; food and agriculture; housing and
construction; medical and pharmaceutical; and personal care, cosmetics
and other consumer products. Within each of these sectors, GAO also
identified a wide variety of other uses that are currently under
development and are expected to be available in the future.
The extent to which nanomaterials present a risk to human health and
the environment depends on a combination of the toxicity of specific
nanomaterials and the route and level of exposure to these materials.
Although the body of research related to nanomaterials is growing, the
current understanding of the risks posed by these materials is
limited. This is because the manner in which some studies have been
conducted does not allow for valid comparisons with newer studies or
because there has been a greater focus on certain nanomaterials and
not others. Moreover, the ability to conduct necessary research on the
toxicity and risks of nanomaterials may be further hampered by the
lack of tools to conduct such studies and the lack of models to
predict the characteristics of nanomaterials.
EPA has undertaken a multipronged approach to understanding and
regulating the risks of nanomaterials, including conducting research
and implementing a voluntary data collection program. Furthermore,
under its existing statutory framework, EPA has regulated some
nanomaterials but not others. Although EPA is planning to issue
additional regulations later this year, these changes have not yet
gone into effect and products may be entering the market without EPA
review of all available information on their potential risk. Moreover,
EPA faces challenges in effectively regulating nanomaterials that may
be released in air, water, and waste because it lacks the technology
to monitor and characterize these materials or the statutes include
volume based regulatory thresholds that may be too high for
effectively regulating the production and disposal of nanomaterials.
Like the United States, Australia, Canada, the United Kingdom, and the
European Union have begun collecting data to understand the potential
risks associated with nanomaterials and are reviewing their
legislative authorities to determine the need for modifications.
Australia and the United Kingdom have undertaken a voluntary data
collection approach whereas Canada plans to require companies to
submit certain types of information. Some U.S. states, like
California, have also begun to address the potential risks from
nanomaterials by, for example, collecting information from
manufacturers on a limited number of nanomaterials in use in those
states and making some of this information publicly available.
What GAO Recommends:
GAO recommends that EPA complete its plans to modify its regulatory
framework for nanomaterials as needed. EPA concurred with our
recommendations and provided technical comments, which we incorporated
as appropriate.
View [hyperlink, http://www.gao.gov/products/GAO-10-549] or key
components. For more information, contact Anu Mittal at (202) 512-3841
or mittala@gao.gov.
[End of section]
Contents:
Letter:
Background:
Nanomaterials Currently Enhance Products across a Number of Industry
Sectors, and New Uses Continue to Be Developed:
Potential Risks to Human Health and the Environment from Nanomaterials
Depend on Toxicity and Exposure, and Current Understanding of the
Risks Is Limited:
EPA Has Taken a Multipronged Approach to Managing the Potential Risks
of Nanomaterials but Faces Various Challenges in Regulating These
Materials:
Other National Authorities Are Collecting Information on Nanomaterials
and Are Evaluating Their Legislation to Ascertain if Changes Are
Needed:
Some State and Local Governments Have Begun to Address the Risks of
Nanomaterials:
Conclusions:
Recommendations for Executive Action:
Agency Comments:
Appendix I: Objectives, Scope, and Methodology:
Appendix II: Comments from the Environmental Protection Agency:
Appendix III: GAO Contact and Staff Acknowledgments:
Related GAO Reports:
Figures:
Figure 1: Examples of Nanomaterials as Raw Materials, Intermediates,
and Finished Products:
Figure 2: Examples of Current and Potential Nanotechnology Innovations
that May Be Used in an Automobile:
Figure 3: Examples of Current and Potential Nanotechnology Innovations
That May Be Used in a Mobile Phone:
Figure 4: Examples of Current and Potential Nanotechnology Innovations
That May Be Used in a Drink Bottle:
Figure 5: Examples of Current and Potential Nanotechnology Innovations
That May Be Used in a House:
Figure 6: Potential Exposure Routes throughout the Life Cycle of
Nanomaterials:
Figure 7: The Increase in Environment and Human Safety Research
Relating to Nanomaterials since 2005:
Abbreviations:
CERCLA: Comprehensive Environmental Response, Compensation, and
Liability Act:
EPA: Environmental Protection Agency:
FIFRA: Federal Insecticide, Fungicide, and Rodenticide Act:
ISO: International Organization for Standardization:
NICNAS: National Industrial Chemicals Notification and Assessment
Scheme:
NNI: National Nanotechnology Initiative:
OECD: Organisation for Economic Co-operation and Development:
RCRA: Resource Conservation and Recovery Act:
REACH: Regulation, Evaluation and Authorization of Chemicals:
SNUR: Significant New Use Rule:
TSCA: Toxic Substances Control Act of 1976:
UV: ultraviolet:
Wilson Center: Woodrow Wilson International Center for Scholars'
Project on Emerging Nanotechnologies:
[End of section]
United States Government Accountability Office:
Washington, DC 20548:
May 25, 2010:
The Honorable Barbara Boxer:
Chairman:
Committee on Environment and Public Works: United States Senate:
Dear Madam Chairman:
The term "nanotechnology" encompasses a wide range of innovations
based on the understanding and control of matter at the scale of
nanometers--the equivalent of one-billionth of a meter. For
illustration, a sheet of paper is about 100,000 nanometers thick, a
human hair is about 80,000 nanometers wide, and three gold atoms lying
side by side are about 1 nanometer long. Unusual properties can emerge
in materials manufactured at the nanoscale--including catalytic,
electrical, magnetic, mechanical, optical, and thermal properties--
that differ in important ways from the properties of conventionally
scaled materials. Some of these new properties can enhance products
and their applications across a number of sectors, including
electronics, medicine, and defense. The world market for
nanotechnology-related products is growing and is expected to total
between $1 trillion and $2.6 trillion by 2015.
Nanomaterials can occur naturally, be created incidentally, or be
manufactured intentionally. For example, naturally occurring
nanomaterials can be found in volcanic ash, forest fire smoke, and
ocean spray. Incidental nanomaterials are by-products of industrial
processes, such as mining and metal working, and combustion engines,
such as those used in cars, trucks, and some trains. In contrast,
manufactured nanomaterials (sometimes called engineered nanomaterials)
have been specifically designed for a particular function or property,
such as improved strength, decreased weight, or increased electrical
conductivity. Our review will focus on manufactured nanomaterials,
rather than nano-sized materials that occur naturally in the
environment or are incidentally produced, and for the remainder of
this report, we will call such materials "manufactured nanomaterials,"
or simply "nanomaterials." While the use of nanomaterials holds
promise for the future, their small size and unique properties raise
questions about potential risks to people or the environment that
might result from exposure to them during their manufacture, use, and
disposal. Risk is usually defined as the potential for harmful effects
to human health or the environment resulting from exposure to a
substance--in this case, nanomaterials. In general terms, risk depends
on a combination of the exposure a person or the environment has to
the substance as well as the inherent toxicity of the chemical. In
other words, the same exposure to two different substances each with
their own toxicity would result in different levels of potential risk.
The Environmental Protection Agency (EPA) administers several laws
that regulate chemicals, pesticides, pollutants in air or water, and
wastes that may be composed of or contain nanomaterials.[Footnote 1]
These laws include the following:
* the Toxic Substances Control Act of 1976 (TSCA), which authorizes
EPA to require chemical companies to report certain information about
chemicals used in commerce and authorizes EPA to require testing of
and control chemicals that pose an unreasonable risk to human health
or the environment, among other things;
* the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA),
which authorizes EPA to regulate the sale and use of pesticides and
prohibits marketing of pesticides that have not been registered with
EPA;[Footnote 2]
* the Clean Air Act, which requires EPA to set standards for common
air pollutants and to regulate industrial sources of hazardous air
pollutants;
* the Clean Water Act, which authorizes EPA to regulate discharges of
pollutants into federally regulated waters;
* the Resource Conservation and Recovery Act (RCRA), which establishes
a framework for regulation of hazardous and solid wastes and
authorizes EPA to issue administrative orders to address imminent
hazards; and:
* the Comprehensive Environmental Response, Compensation, and
Liability Act (CERCLA), commonly known as Superfund, which authorizes
EPA to compel parties responsible for contaminating sites to clean
them up or to conduct cleanups itself and then seek reimbursement from
responsible parties.
On the international level, other national authorities are also
concerned about the potential risks of nanomaterials and whether their
current regulatory framework authorities are sufficient to address
these risks. For example, Australia, Canada, the United Kingdom, and
the European Union have begun to review their regulatory approaches
for nanomaterials. Furthermore, the Organisation for Economic Co-
operation and Development--a forum in which the governments of 30
developed countries, including the United States, work together to
address economic, social, and environmental issues--has established a
"working party" on nanomaterials. In addition to the international
focus on this topic, some U.S. states have begun to explore ways to
address the potential risks of nanomaterials.
In this context, you asked us to (1) identify examples of current and
potential uses of nanomaterials, (2) determine what is known about the
potential human health and environmental risks from nanomaterials, (3)
specifically assess actions EPA has taken to better understand and
regulate the risks posed by nanomaterials as well as its authorities
to do so, and (4) identify approaches that selected other national
authorities have taken to address the risks associated with
nanomaterials. In addition, you asked us to identify any U.S. states
and localities that have begun to address the risks from nanomaterials.
To identify examples of current and potential uses of manufactured
nanomaterials, we analyzed documents and reports that discuss the
current and future uses of manufactured nanomaterials, such as market
research reports produced by Lux Research, an independent research
firm that conducts market analysis of nanotechnology, among other
things. In addition, we interviewed cognizant agency officials from
the six U.S. agencies that conduct the majority of nanotechnology-
related research.[Footnote 3] We also interviewed knowledgeable
stakeholders, including officials from the National Nanotechnology
Initiative, the Wilson Center, the National Academy of Sciences, Lux
Research, and the NanoBusiness Alliance--a nanotechnology-related
business association. We used an iterative process, often referred to
as "snowball sampling," to identify knowledgeable stakeholders, and we
selected for interviews those who would provide us with a broad range
of perspectives on the current and potential uses of nanomaterials.
To determine what is known about the potential human health and
environmental risks of manufactured nanomaterials, we reviewed
documents that had been published by peer-reviewed journals,
government agencies, and international nonprofit organizations. In
conducting this review, we searched databases, asked knowledgeable
stakeholders to identify relevant studies, and reviewed studies from
article bibliographies to identify additional sources of information
on the potential risks. Our review focused on 20 such studies,
selected in part because they provided a synthesis of available
research related to nanomaterials' risks and covered a variety of
nanomaterials. For the purposes of this report, all the documents,
studies, and synthesis studies we reviewed will be referred to as
"studies." We also spoke with a variety of knowledgeable stakeholders
representing industry, academia, nongovernmental organizations, and
the regulatory community. These knowledgeable stakeholders were also
selected using a snowball sampling method.
To assess actions EPA has taken to better understand and regulate
manufactured nanomaterials and its authorities to do so, we analyzed
selected laws and regulations, including TSCA, FIFRA, the Clean Air
Act, the Clean Water Act, RCRA, and CERCLA. We also reviewed data and
reports on EPA's Nanoscale Materials Stewardship Program, which EPA
developed to encourage companies to voluntarily develop and submit
information to the agency on the characteristics of nanomaterials.
Furthermore, we consulted with EPA officials and legal experts to
obtain their perspectives on EPA's available authorities to regulate
manufactured nanomaterials.
To identify the approaches that other selected national authorities-
Australia, Canada, the United Kingdom, and the European Union--have
used to address the potential risks associated with manufactured
nanomaterials, we analyzed these authorities' laws and regulations
that would be applicable to regulating manufactured nanomaterials. We
selected these authorities based on interviews with knowledgeable
stakeholders who identified them as having taken actions related to
better understanding, assessing, or regulating the potential risks of
nanomaterials. To identify any states that may be taking action with
regard to nanomaterials, we spoke with federal regulators; industry
and environmental groups; and other knowledgeable stakeholders,
including the Environmental Council of States.
A more detailed description of our scope and methodology is presented
in appendix I. We performed our work between May 2009 and May 2010, in
accordance with generally accepted government auditing standards.
Those standards require that we plan and perform the audit to obtain
sufficient, appropriate evidence to provide a reasonable basis for our
findings and conclusions based on our audit objectives. We believe
that the evidence obtained provides a reasonable basis for our
findings and conclusions based on our audit objectives.
Background:
In fiscal year 2009, federal support for nanotechnology research
totaled about $1.7 billion. Cumulatively from fiscal year 2001 through
fiscal year 2009, federal agencies have devoted over $10.5 billion to
nanotechnology research. To guide federal development of
nanotechnology, the National Nanotechnology Initiative (NNI) was
established in 2001 to support long-term research and development
aimed at accelerating the discovery, development, and deployment of
nanoscale science, engineering, and technology. The NNI is a mechanism
to coordinate the nanotechnology-related activities of the 25
currently participating federal agencies that fund nanoscale research
or have a stake in the outcome of this research, such as those
agencies that may regulate products containing nanomaterials. While
the NNI is designed to facilitate intergovernmental cooperation and
identify overarching goals and priorities for nanotechnology research,
it is not a research program and has no funding or authority to
dictate the nanotechnology research agenda for participating agencies
or to ensure that adequate resources are available to achieve specific
goals. Instead, participating agencies develop and fund their own
nanotechnology research agendas. In fiscal year 2009, six NNI agencies
accounted for over 95 percent of federal nanotechnology research
reported. These are the Department of Defense, the Department of
Energy, EPA, the Department of Health and Human Services' National
Institutes of Health, the Department of Commerce's National Institute
of Standards and Technology, and the National Science Foundation.
Nanomaterials can take a variety of forms and can generally be
organized into four types:
* Carbon-based materials. These nanomaterials are composed mostly of
carbon, and are most commonly spherical, elliptical, or tubular in
shape. Spherical and elliptical carbon shapes are referred to as
fullerenes, while tubular ones are called nanotubes.
* Metal-based materials. These nanomaterials include nanoscale gold,
nanoscale silver, and metal oxides, such as titanium dioxide. They
also include quantum dots, which are closely packed semiconductor
crystals comprised of hundreds or thousands of atoms, on the scale of
a few nanometers to a few hundred nanometers.
* Dendrimers. These nanomaterials are nanoscale polymers built from
branched units. The surface of a dendrimer has numerous branch ends,
which can be tailored to perform specific chemical functions. Also,
some dendrimers contain interior cavities into which other molecules
can be placed, such as for drug delivery.
* Composites. These materials combine nanoparticles with other
nanoparticles or with larger, conventional-scale materials. For
example, nanoparticles, such as nanoscale clay can be combined with
other materials to form a composite material.
EPA uses a risk assessment process to estimate the extent of harm, if
any, that can be expected from exposure to a given substance
throughout its life cycle and to help regulators determine whether the
risk meets the requirements for taking action under its statutory
authorities, such as banning the substance's production or limiting
its use. The basic risk assessment paradigm includes the following:
* an evaluation of scientific information on a substance's hazardous
properties--or toxicity--which may potentially affect human health or
the environment;
* the dose-response relationship--the relationship between the extent
of exposure (dose) and the resulting changes in health or body
function (response)--describes the toxic effect of a substance; and:
* exposure--the extent to which humans or the environment are expected
to be exposed to the chemical.
EPA is applying this risk assessment paradigm to assess the potential
risks from nanomaterials. EPA officials also told us that risk
assessment is not the only means of using scientific information to
inform decision making. For example, they said that by using green
chemistry and life cycle assessment approaches,[Footnote 4] a
material's properties may be modified or exposure controls
incorporated to minimize and manage potential risk.
Nanotechnology is an example of a fast-paced technology that poses
challenges to agencies' policy development and foresight efforts. We
have conducted past work looking at the challenges of exercising
foresight when addressing potentially significant but somewhat
uncertain trends,[Footnote 5] including technology-based trends that
proceed at a high "clockspeed," that is, a (1) faster pace than trends
an agency has dealt with previously or (2) quantitative rate of change
that is either exponential or exhibits a pattern of doubling or
tripling within 3 or 4 years, possibly on a repeated basis.[Footnote
6] As our prior work has noted, when an agency responsible for
ensuring safety faces a set of potentially significant high-clockspeed
technology-based trends, it may successfully exercise foresight by
carrying out activities such as:
* considering what is known about the safety impact of the trend and
deciding how to respond to it;
* reducing uncertainty as needed by developing additional evidence
about the safety of the trend; and:
* communicating with Congress and others about the trends, agency
responses, and policy implications.
Similarly, our 21st Century Challenges report raised concern about
whether federal agencies are poised to address fast-paced technology-
based challenges.[Footnote 7] Other foresight literature illustrates
the potential future consequences of falling behind a damaging trend
that could be countered by early action. These analyses suggest that
unless agencies and Congress can stay abreast of technological
changes, such as nanotechnology, they may find themselves "in a
constant catch-up position and lose the capacity to shape outcomes."
[Footnote 8]
Nanomaterials Currently Enhance Products across a Number of Industry
Sectors, and New Uses Continue to Be Developed:
Industries around the world are harnessing the properties of
nanomaterials for a variety of products across a number of sectors and
are expected to continue to find new uses for these materials.
Nanomaterials can enter the marketplace as materials themselves, as
intermediates that either have nanoscale features or incorporate
nanomaterials, and as final nano-enabled products (see figure 1). For
example, a manufacturer of clay nanoparticles can provide them to a
plastic manufacturer, who can use them to enhance a composite material
(an intermediate). The plastic manufacturer can then sell the
composite material to an automobile manufacturer, who can use the
material to mold parts for cars (nano-enabled products).
Figure 1: Examples of Nanomaterials as Raw Materials, Intermediates,
and Finished Products:
[Refer to PDF for image: illustration]
Nanomaterials: Nanoscale structures in unprocessed form:
Such as:
* Carbon nanotubes;
* Ceramic nanoparticles;
* Dendrimers;
* Fullerenes;
* Metal nanoparticles;
* Nanostructured metals;
* Nanowires.
Nanointermediates: Intermediate products with nanoscale features:
Such as:
* Catalysts;
* Coatings;
* Composites;
* Displays;
* Drug delivery systems;
* Energy storage;
* Sensors.
Nano-enabled products: Finished goods incorporating nanotechnology:
Such as:
* Automobiles;
* Bottles;
* Buildings;
* Cancer treatment;
* Mobile phones.
Source: Adapted by GAO from materials produced by Lux Research.
[End of figure]
As the uses of nanomaterials continue to evolve, the overall market
for them is growing, along with the degree to which they are
permeating our everyday lives. In 2009, the Woodrow Wilson
International Center for Scholars' Project on Emerging
Nanotechnologies (Wilson Center) identified a list of more than 1,000
nano-enabled products currently on the market, reflecting a 379
percent increase since this list was first compiled in 2006.[Footnote
9] The list contains information on products from over 20 countries
that can be purchased and used by consumers and provides a baseline
for understanding the extent to which nanotechnology is being used. As
the Wilson Center has reported, the trend of an increased number of
products and applications featuring nanomaterials is also reflected in
the number of nanotechnology patents issued by the U.S. Patent and
Trademark Office, growing from 125 in 1985 to 4,995 in 2005, which
represents a compound annual growth rate of 20 percent. The following
is a list of selected industry sectors and some examples of current
and potential uses of nanomaterials within each sector that illustrate
the ubiquitous nature of these materials in commerce. Because
assembling a complete catalog of uses would be difficult in an
evolving, dynamic industry, the list is not comprehensive, the
examples chosen are simply illustrative, and we have not verified the
claims made by the manufacturers of the products used in these
examples.
Automotive:
From car bodies to exterior coatings to engines on the market today,
cars contain numerous enhancements made possible by nanomaterials. In
the current marketplace, some bumpers and other auto parts incorporate
composite materials containing nanomaterials, such as nanoscale clays,
metals, and carbon nanotubes to make these parts stronger, and more
fire resistant.[Footnote 10] Many nano-enabled products in the
automotive sector involve the addition of nanoscale ceramic and metal
particles to a wide variety of coatings. These nanomaterials provide
advantages for coatings over conventional materials, such as the
ability to block ultraviolet (UV) light or promote self-cleaning
without altering the transparency of the coatings. For example,
coatings containing nanoparticles are currently dispersed in paints
and pigments to make surfaces stronger, smoother, more scratch and
stain resistant, waterproof, or some combination of these and other
properties. In addition, carbon nanotubes offer an especially high
tensile strength--the ability to withstand a stretching force without
breaking--of about 100 times greater than that of steel at one-sixth
the weight, and their electrical conductivity can be precisely
controlled, which helps prevent the build-up of static electricity. As
a result, when a manufacturer of fuel lines adds carbon nanotubes to
traditional engineering materials, it results in stronger, safer fuel
lines.
In the future, nanomaterials could be used to improve the performance
of cars, including reducing wear on engine parts and increasing
battery power and fuel efficiency. For example, lubricants that
contain certain nanomaterials could provide smaller, stronger, and
more stable alternatives to oil-based lubricants. In addition,
electrodes--electrical conductors that contain movable electric
charges--manufactured at the nanoscale could enable higher-performance
rechargeable batteries. For example, according to documents we
reviewed, one company that is developing a new lithium-ion battery for
electric vehicles uses nanoscale metal oxide materials to create
crystallized nanoparticles that may enable this nano-enabled battery
to deliver 20 percent more power. Moreover, fuel additives with
nanoparticles of cerium oxide could increase diesel engine fuel
efficiency.[Footnote 11] One British company has developed such an
application for a fuel-based additive that, due to the size-based
properties of cerium nanoparticles, creates a greater surface area for
catalyzing the combustion reactions between diesel and air.[Footnote
12] According to this company, the result is a cleaner burn that
converts more fuel to carbon dioxide, produces less noxious exhaust,
and deposits less carbon on the engine cylinder walls than other fuel
additives. Figure 2 shows examples of some current and potential
nanotechnology innovations that may be used in automobiles.
Figure 2: Examples of Current and Potential Nanotechnology Innovations
that May Be Used in an Automobile:
[Refer to PDF for image: illustration]
* Lubricating nanocoating on engine parts improves fuel economy;
* Carbon nanotube fuel line lessens risk of fire;
* Nanocomposite body moldings are lighter than conventional materials;
* Magnetic nanomaterial for memory chips may remove need for battery;
* Nanocoating improves scratch resistance;
* Nanoscale catalysts allow reduction in emissions.
Source: Adapted by GAO from materials produced by Lux Research.
Note: The photo is illustrative and not intended to imply that this
particular vehicle currently utilizes the nanotechnology innovations
depicted or will in the future.
[End of figure]
Defense and Aerospace:
Nanomaterials are beginning to be used in aerospace applications by
manufacturers seeking to take advantage of the electrical and
mechanical strength advantages they offer and by the Department of
Defense, which is seeking ways to enhance the tools available to its
soldiers and the effectiveness of its weapons systems. Nanomaterial
polymers are currently being used as sensors that detect very small
traces of explosives, which indicate the presence of buried landmines,
according to Department officials. In addition, according to documents
we reviewed, stronger and lighter planes that are better protected
against lightning and fire have been made possible by using carbon
nanotubes and other nanostructured materials. For example, one company
has created a nanolaminated material used for planes that is comprised
of layers of metal alloys that are stronger, lighter, and more energy
absorbent than steel. In addition, polymers with embedded silver
nanoparticles are helping to keep surfaces, including the interiors of
aircraft, free of microbes.[Footnote 13] The polymers contain
nanoscale silver particles that, when added to a product's surface,
release ions that kill bacteria existing on the surface.[Footnote 14]
Companies are also introducing nanostructured alternatives to standard
copper wiring. For example, one company has developed a process to
create highly conductive sheets of fabric and lengths of yarn
containing carbon nanotubes that can be used to create wiring and
cables for airplanes and satellites that weigh much less than
traditional copper wire.
In the future, nanomaterials may help enable the development of new
applications and products across a wide spectrum in the defense arena,
including surveillance devices, explosives and propellants, and
uniforms. For example, according to Department of Defense officials
and documents we reviewed, nearly "invisible" surveillance may be
possible through the incorporation and integration of different
nanotechnologies, including radio frequency identification chips;
integrated circuits; minute biosensors; and "intelligent" fabrics,
films, and surfaces. Miniaturized surveillance techniques under
research include using live insects ("spy" bees) tagged with
nanomaterials or tiny winged robots that emulate insects to fly into
an enemy situation to record data. In addition, more powerful
conventional explosives and faster moving missiles may be possible due
to the greater amounts of energy provided by nanostructured aluminum.
In combination with metal oxides, such as iron oxide, nanostructured
aluminum allows many more chemical reactions to occur in a given
surface area, increasing the explosive force. Also, nanomaterials such
as carbon nanotubes embedded in fabric could allow for lighter
uniforms and multifunctional combat suits for soldiers. The uniforms
could potentially, for example, change color to match the environment,
become rigid casts to protect injuries, or help block bullets and
chemical/biological agents. The material could even incorporate
sensors that monitor a soldier's condition, or function as drug
dispensers activated automatically via radio waves by a remote doctor.
Electronics and Computers:
Computers and consumer electronics have also begun to benefit from the
advantages nanomaterials offer, including improved display screens and
improved electrical conductivity. Carbon nanotubes, quantum dots,
[Footnote 15] and nanoscale layers of polymers can improve the
properties of displays. For example, one company has developed an
ultra-thin, layered system of polymers that, unlike conventional
liquid crystal displays, requires no backlights or filters. The images
are brighter and clearer, and the technology could make possible fully
bendable plastic displays, according to the company. In addition,
since nanomaterials often enhance electrical conductivity, metallic
nanoparticles and carbon nanotubes are being used in a growing number
of conductive coatings, such as those used for touchscreens and solar
cells. According to documents we reviewed, one company sells a
transparent conductive coating and a coated film, both incorporating
nanowires, which conduct electricity better than traditional
materials. The coating and film could eventually replace rare and
expensive indium tin oxide, currently the most widely used transparent
conductor in the display industry. Moreover, nanomaterials such as
lead-free, conductive adhesives could eliminate several steps in
manufacturing electronics and could lead eventually to elimination of
some or all of the 3,900 tons of toxic, leaded solder used every year
by the U.S. electronics industry, according to an EPA document.
In the future, computers and electronic devices could employ
nanomaterials to create more efficient data storage and longer-
lasting, rechargeable batteries. Memory storage devices could become
more powerful through a variety of nanotechnology applications. New
methods of storing information electronically are emerging from a
variety of applications aimed at increasing the amount of information
that can be stored on a given physical space. For example, one company
has demonstrated the potential to create high-density memory devices
with an estimated storage capacity of 1 terabyte per square inch--more
than 200 times higher than the storage density of a DVD--by storing
information mechanically using nanoscale probes to punch nanoscale
indentations into a thin plastic film.[Footnote 16] In addition,
companies, research institutions, and government labs are working to
develop nano-based technology that could perfect "microbatteries,"
which are smaller, cheaper, and more powerful than batteries currently
in use. The greater surface area of the nanowires used in these
batteries lowers the internal resistance of the battery and therefore
allows greater current flow. Figure 3 shows some examples of current
and potential nanotechnology innovations that may be used in a mobile
phone.
Figure 3: Examples of Current and Potential Nanotechnology Innovations
That May Be Used in a Mobile Phone:
[Refer to PDF for image: illustration]
* Nanocomposite plastics are lighter and stronger;
* Nanomaterials make batteries lighter and longer lasting;
* Nanomaterials enable faster memory;
* Nanostructured optical components allow better images;
* Nano-enabled light emitting diode or light emitting polymer displays
are lighter and cheaper;
* Antimicrobial nanocoating resists bacteria.
Source: Adapted by GAO from materials produced by Lux Research.
Note: The photo is illustrative and not intended to imply that this
particular phone currently utilizes the nanotechnology innovations
depicted or will in the future.
[End of figure]
Energy and Environment:
Companies are beginning to use nanomaterials to clean up waste,
substitute nonrenewable resources with renewable ones, reduce
pollution, and increase the efficiency of solar power. Because
nanoscale particles can be more chemically reactive than
conventionally scaled particles of the same substance due to their
large surface area to volume ratio, these materials can be useful for
environmental remediation. Specifically, the increased surface area of
various types of ceramic or metal nanomaterials can result in the
rapid reduction of contaminant concentrations in soil, water, and air,
as pollutants or toxins in these media react with the nanomaterials.
Similarly, nanoscale iron is being deployed in a growing number of
environmental remediation projects with results that are proving
successful so far, according to EPA officials. For example, at one
remediation project, researchers injected carbon infused with
nanoparticles of iron into contaminated soil and found that the
nanoparticles made the resulting material more effective at absorbing
contaminants than similar materials without the nanoparticles. In
addition, nanomaterials are being used to create packaging materials
made from waste. For example, one company produces nanoparticle paper
coatings made from renewable natural starches that can replace
conventional material in paper coatings, which is typically made from
nonrenewable petroleum. Nanomaterials are also being used to improve
automotive catalytic converters, which feature nano-enabled catalysts
that reduce air pollution more efficiently. One company is
manufacturing a catalyst consisting of nanostructures with surface
areas much higher than traditional materials and that allows catalytic
converters to remain effective under prolonged exposure to high
temperatures, resulting in more stable, durable, and cost-effective
products. In the energy arena, nano-enabled thin-film and photovoltaic
technologies are making solar power more efficient. For example, one
company has reported gains in the ability of its thin-film solar cell
materials to absorb light, because the structure of the nanomaterial
is much smaller than the wavelength of light, which allows it to act
like an antenna that concentrates, absorbs, and transfers energy with
high efficiency.
In the future, nanomaterials could help deliver alternative forms of
energy, cleaner water, and more efficient energy transmission. Using
nanoscale catalysts, hydrogen--an alternative form of energy--could be
produced from water more efficiently. For example, a company has
developed a photoelectrode that uses nanoscale material and converts
sunlight into hydrogen six times more efficiently than its
conventionally scaled equivalent.[Footnote 17] In addition,
nanotechnology-enabled water desalination and filtration systems may
offer affordable, scalable, and portable water filtration in the
future. Filters, comprised of nanoscale pores which incorporate a wide
variety of nanomaterials--including nanoparticles made of aluminum
oxide, iron, and gold, and carbon nanotubes--have the potential to
allow water molecules to pass through, but screen out larger
molecules, such as salt ions and other impurities such as bacteria,
viruses, heavy metals, and organic material. In addition,
nanoparticles could be used to improve the efficiency of energy
transmission by increasing the capacity and durability of insulation
for underground electrical cables, allowing cables of smaller diameter
to carry the same power as larger cables and to last longer. For
example, one company's research shows that cable insulation treated
with nanocomposites containing nanosilica have about 100 times longer
voltage endurance compared to untreated material. In addition,
researchers have demonstrated that carbon nanotube fiber bundles could
carry 100 times more electrical current than the leading transmission
wires, without as much energy loss. Moreover, one study predicts that
if energy transmission losses could be reduced from the current 7
percent using copper wires to 6 percent by using carbon nanotube
fibers, the annual energy savings in the United States would be equal
to 24 million barrels of oil.
Food and Agriculture:
Nanomaterials are currently appearing in food packaging and food
supplements.[Footnote 18] Specifically, nanomaterials are being used
in food packaging, where applications such as antimicrobial nanofilms--
thin layers of substances meant to hamper the growth of bacteria and
fungi--are intended to bolster food safety. Also, composite materials
made of nanoclays embedded in nylon can offer strong oxygen and carbon
dioxide barriers and have been used in plastic bottles and films for
packaging food and beverages. For example, one company produces a
nylon and clay nanocomposite used as a flexible, puncture-resistant
oxygen barrier for beer and carbonated beverage bottles; in packaging
for processed meats and cheeses; and in coatings for paper packaging
for juice or dairy products. Moreover, products such as cutting boards
and food containers have been infused with nanosilver--which is known
for its antimicrobial properties. In addition, encapsulation--the
process of using one material to deliver another material inside the
human body--has been in use for decades but is being improved with
nanomaterials. Nanoencapsulated food products and supplements can
target nutrients, release drugs on a controlled schedule, and mask
tastes. For example, some vitamins can be difficult to deliver in
beverages because they degrade and may not be easily absorbed by the
body. One company has developed nanoscale structures to deliver the
vitamin to the digestive system, making it easier for absorption to
occur. Another manufacturer has used nanocapsules to incorporate
certain fatty acids that have purported health benefits into bread.
The company claims the acids in the nanocapsules bypass the taste
buds, emerging only after the nanocapsules reach the stomach, thus
avoiding any unpleasant taste.
In the future, manufactured nanomaterials could be used to enhance
agriculture; monitor food quality and freshness; improve the ability
to track food products from point of origin to retail sale; and modify
the taste, texture, and fat content of food. Nanomaterials are being
developed to more efficiently and safely administer pesticides,
herbicides, and fertilizers by controlling more precisely when and
where they are released. In addition, researchers are developing a
nanoscale powder that can retain water better than other materials and
allows fertilizers to gradually release nutrients for crops or grass,
according to the Wilson Center. In addition, researchers have
developed nanobiosensors using nanoscale particles for detecting
bacteria, such as salmonella, in water and liquid food. Their work
could lead to nanosensors that could be used in fields to monitor for
bacterial contamination of crops, such as spinach, lettuce, and
tomatoes, potentially reducing the spread of food-borne illnesses. In
addition, electrically conductive inks containing nanomaterials could
be used to print radio-frequency identification tags, which could be
integrated into packaging for food products, potentially resulting in
improved food security and better inventory tracking and management.
Figure 4 shows some examples of current and potential nanotechnology
innovations that may be used in a drink bottle.
Figure 4: Examples of Current and Potential Nanotechnology Innovations
That May Be Used in a Drink Bottle:
[Refer to PDF for image: illustration]
* Nanoencapsulated carriers deliver food and dietary supplements;
* Nanosensors detect changes in food and beverage quality;
* Gas barrier nanocoatings keep food and beverages fresher;
* Coatings and plastics containing nanomaterials block ultraviolet
light;
* Nanosilver antimicrobial coating resists bacteria;
* Electrically conductive inks containing nanoparticles make radio
frequency identification tag printable.
Source: Adapted by GAO from materials produced by Lux Research.
Note: The photo is illustrative and not intended to imply that this
particular juice bottle currently utilizes the nanotechnology
innovations depicted or will in the future.
[End of figure]
Housing and Construction:
Materials and coatings are currently making buildings and homes
cleaner and stronger, and in the future will allow them to operate
with higher energy efficiency, according to documents we reviewed.
Protective coatings and materials that incorporate nanoparticles of
titanium dioxide are being used to manage heat and light by blocking
UV light from the sun's rays and are taking on self-cleaning
properties through a photocatalytic effect.[Footnote 19] For example,
titanium dioxide is being added to paints, cements, windows, tiles,
and other products for its sterilizing and deodorizing properties.
Additionally, as titanium dioxide is exposed to UV light, it becomes
increasingly hydrophilic--attractive to water--and is therefore being
used for antifogging coatings or self-cleaning windows. Nanomaterials
are also proving beneficial to the construction industry by, for
example, making steel tougher and concrete stronger, more durable, and
more easily placed. For example, one company has created a structural
material with a grain size reduced to the 100 nanometer scale, which
it claims has a strength-to-density ratio four times that of the
toughest titanium alloys and also resists corrosion. Inside the walls
of buildings, insulation made from nanomaterials is providing high
thermal performance at minimal weight and thickness. In addition,
nanomaterials are being incorporated into some air monitoring
technologies, air purification products, and energy-efficient air
conditioning systems for residential, commercial, and industrial
settings. For example, some air filters that are on the market use
nanomaterials to clean air better than conventional materials.
In the future, nanoparticle coatings on windows and buildings could
retain energy from the sun for later release. For example, researchers
working on phase change materials--materials which absorb and release
thermal energy--have found that when graphite nanofibers are blended
into these materials the nanofibers improve the material's thermal
performance. The result could be cheaper and more efficient uses of
these materials for solar energy storage. In addition, nanomaterials
may offer approaches that enable materials to "self-heal" by
incorporating, for example, nanocontainers of a repair substance
(e.g., an epoxy) throughout the material. When a crack or corrosion
reaches a nanocontainer, it could be designed to open and release its
repair material to fill the gap and seal the crack. Figure 5 shows
some examples of current and potential nanotechnology innovations that
may be used in a house.
Figure 5: Examples of Current and Potential Nanotechnology Innovations
That May Be Used in a House:
[Refer to PDF for image: illustration]
* Nanomaterials allow solar cells to be integrated into roof material;
* Nanoporous materials make insulation more efficient;
* Self-cleaning, nanostructured window coatings loosen dirt so windows
can self-clean;
* Nanocomposite materials make drywall stronger;
* Nanocoatings make bathroom surfaces easy to clean;
* Nanoparticles make paint durable and mildew resistant.
Source: Adapted by GAO from materials produced by Lux Research.
Note: The photo is illustrative and not intended to imply that this
particular house currently utilizes the nanotechnology innovations
depicted or will in the future.
[End of figure]
Medical and Pharmaceutical:
Nanotechnology is important to the medical and pharmaceutical industry
because the extremely small size of nanomaterials makes possible
medical interventions that can be directed to individual cell types,
allowing for better diagnosis, treatment, and prevention of cancer and
other deadly diseases.[Footnote 20] Current disease detection efforts
include the use of nanoscale sensors to identify biomarkers, such as
altered genes, that may provide an early indicator of cancer. Doctors
are also using nanomaterials as markers to enhance images from deep
inside human tissue, allowing them to track particles to the site of a
tumor, resulting in earlier detection of tumors. Certain nanomaterials
such as polymer nanoparticles are being used to treat cancer by
delivering medication directly to tumors while sparing healthy tissue.
In addition, silver nanocrystals are being used in antimicrobial wound
dressings, thereby requiring fewer dressing changes and causing
patients less pain.
In the future, nanomaterials could be used to help doctors better
diagnose and treat disease. In diagnosis, nanomaterials hold promise
for showing the presence, location, and contours of cardiovascular and
neurological disease, and small tumors. For example, researchers could
use metallic and magnetic nanoparticles to enhance imaging, the
results of which can be used to guide surgical procedures and to
monitor the effectiveness of nonsurgical therapies in reversing the
disease or slowing its progression. In the future, sensors implanted
or delivered with a drug could allow for continuous and detailed
health monitoring so disease might be managed better, turning a drug
into a multifunctional tool for diagnosis and treatment. For example,
bio-sensors could be attached to targeted drugs and linked to a
mechanism that reports the body's condition. Furthermore, according to
the National Institutes of Health, gold nanoshells are being developed
to simultaneously image and destroy cancer cells using infrared light.
Nanoshells can be designed to absorb light of different frequencies,
generating heat. Once the cancer cells take up the nanoshells,
scientists apply near-infrared light that is absorbed by the
nanoshells, creating an intense heat inside the tumor that selectively
kills tumor cells without disturbing neighboring healthy cells. Such a
targeted delivery approach could reduce the amount of chemotherapy
drug needed to kill cancer cells, potentially reducing the side
effects of chemotherapy. Medical researchers are also exploring the
use of nanomaterials to deliver molecules and growth factors to
promote better healing for burns and wounds that heal without scars.
For example, Department of Defense researchers have conducted tests in
animals using nanofiber mesh scaffolds to treat bone, nerve,
cartilage, and muscle injuries and have reported that preclinical data
from the studies indicate improved healing. Other nanofibers are being
developed for medical use as mesh barriers to stop the flow of blood
and other fluids more quickly and effectively.
Personal Care, Cosmetics, and Other Consumer Products:
Nanomaterials are currently being used in a variety of personal care
items, cosmetics, and other consumer products.[Footnote 21] These
products include sunscreens that contain nanoscale titanium dioxides
and zinc oxides, which act as physical filters that absorb UV light.
Because these nanomaterials are smaller than the wavelength of light,
they make sunscreens transparent instead of opaque, and they may also
adhere better when applied and absorb harmful ultraviolet rays more
effectively than conventional sunscreens, according to stakeholders
and documents we reviewed. In addition, nanomaterials are being
incorporated into cosmetics, such as an anti-aging cream, which allows
the active ingredients to penetrate deep into the skin where they can
be most effectively administered, according to the manufacturer.
Nanomaterials are also being used in a wide range of other consumer
products. For example, companies are using carbon nanotubes to
reinforce a variety of sporting goods, such as bicycle frames, tennis
rackets, baseball bats, and hockey sticks, because they offer greater
strength and reduced weight, while retaining, or even increasing,
stiffness. Companies are using other nanomaterials to improve the
performance of products such as ski wax and tennis balls. For example,
a nanomaterial coating decreases the gas permeability in tennis balls
and therefore allows the balls to maintain pressure for longer periods
of time, according to the company producing the coating. Nanomaterials
are also being used in coatings to make fabrics and clothing stain and
water resistant. For example, one company embeds nanomaterials on the
surface of fabric fibers, creating a cushion of air around them. The
fabric allows sweat to pass out, while also causing surface water to
bead up and roll off. Another company has developed socks treated with
nanosilver for its antimicrobial properties.
In the future, consumers may benefit from advanced applications that
could emerge from nanomaterial research occurring in a variety of
sectors. For example, developments in the health arena could lead to
new, beneficial pharmaceutical therapies designed to treat aging and
age-related disease. In addition, according to documents we reviewed,
researchers are working to make textiles functional by combining
manufactured nanomaterials with materials that react to light to
create power-generating clothing and nanosilver could be used in
textiles to treat skin conditions. Researchers are also developing
nano-enabled textile surfaces that can remove scratches and scuff
marks, as well as decolorize red wine spills.
Potential Risks to Human Health and the Environment from Nanomaterials
Depend on Toxicity and Exposure, and Current Understanding of the
Risks Is Limited:
The properties of nanomaterials affect their toxicity and, in turn,
their risks to human health and the environment. Furthermore, the risk
of nanomaterials also depends on the extent and route of exposure to
nanomaterials, but current understanding of nanomaterial toxicity and
exposure is limited, according to the studies we reviewed.
The Toxicity of Individual Nanomaterials May Vary According to Their
Properties and Affects Their Risks:
The toxicity of each nanomaterial may vary according to a combination
of the individual properties of these materials--including size,
shape, surface area, and ability to react with other chemicals--and
these properties affect the potential risks posed by nanomaterials,
according to some of the studies we reviewed. The properties of a
nanomaterial may differ from the properties of conventionally scaled
material of the same composition. For example, the properties of
conventionally scaled gold have been well characterized: gold is
metallic yellow in color and does not readily react with other
chemicals. As a nanoparticle, however, gold can vary in color from red
to black and become highly reactive. The following are examples of how
toxicity may be affected by the properties of nanomaterials as
compared with their conventionally scaled counterparts:
* Size. Research assessing the role of particle size on toxicity has
generally found that some nanoscale (
