# Nanotechnology/Environmental Impact#Potential environmental impacts of nanotechnology

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# Potential environmental impacts of nanotechnology

So far most of the focus has been on the potential health and
environmental risks of nanoparticles and only a few studies has been
made of the overall environmental impacts during the life cycle such as
ecological footprint (EF) or life
cycle analysis (LCA). The life cycle
of nanoproducts may involve both risks to human health and environment
as well as environmental impacts associated with the different stages.

The topics of understanding and assessing the environmental impacts and
benefits of nanotechnology throughout the life cycle from extraction of
raw materials to the final disposal have only been addressed in a couple
of studies. The U.S. EPA, NCER have sponsored a few projects to
investigate Life Cycle Assessment methodologies. Only one of these has
yet published results on automotive catalysts [^1] and nanocomposites in
automobiles [^2] , respectively, and one project was sponsored by the
German government [^3] .

A 2007 special issue of Journal of Cleaner Production puts focus on
sustainable development of nanotechnology and includes a recent LCA
study in Switzerland [^4] .

The potential environmental impact of nanomaterials could be more
far-reaching than the potential impact on personal health of free
nanoparticles. Numerous international and national organizations have
recommended that evaluations of nanomaterials be done in a life-cycle
perspective [^5] , [^6],

This is also one conclusion from a recent series of workshops in the US
on "green nanotechnology" (Schmidt, 2007)[^7] .

A workshop co-organised by US EPA/Woodrow Wilson Center and EU
Commission DG Research put focus on the topic of Life Cycle Assessments
of Nanotechnologies (Klöpffer et al., 2007) [^8] .

Heresome of the potential environmental impacts related to
nanotechnological products in their life cycle are discussed followed by
some recommendations to the further work on Life Cycle Assessment (LCA)
of nanotechnological products.

However, when relating to existing experience in micro-manufacturing
(which to a large extent resembles the top-down manufacturing of
nanomaterials) several environmental issues emerge that should be
addressed. There are indications that especially the manufacturing and
the disposal stages may imply considerable environmental impacts. The
toxicological risks to humans and the environment in all life cycle
stages of a nanomaterials have been addressed above. Therefore, the
potentially negative impacts on the environment that will be further
explored in the following are:

-   Increased exploitation and loss of scarce resources;
-   Higher requirement to materials and chemicals;
-   Increased energy demand in production lines;
-   Increased waste production in top down production;
-   Rebound effects (horizontal technology);
-   Increased use of disposable systems;
-   Disassembly and recycling problems.

## Exploitation and loss of scarce resources

Exploitation and loss of scarce resources is a concern since economic
consideration is a primary obstacle to use precious or rare materials in
everyday products. When products get smaller and the components that
include the rare materials reach the nanoscale, economy is not the most
urgent issue since it will not significantly affect the price of the
product. Therefore, developers will be more prone to use materials that
have the exact properties they are searching. For example in the search
for suitable hydrogen storage medias Dillon et al. [^9] experimented
with the use of fullerenes doped with Scandium to increase the
reversible binding of Hydrogen. Other examples are the use of Gallium
and other rare metals in electronics. While an increased usage of such
materials may be foreseen due to the expected widespread use of
nanotechnological products, the recycling will be more difficult (will
be discussed more in detail later), resulting in non-recoverable
dissemination of scarce resources.

## Energy intensity of materials

An issue apart from the loss of resources is the fact that the
extraction of most rare materials uses more energy and generates more
waste than more abundant materials. Table 1 illustrates the energy
intensity of a range of materials. [^10]

  ------------- ---------------------------------------
  Material      Energy intensity of materials (MJ/kg)
  Glass         15
  Steel         59
  Copper        94
  Ferrite       59
  Aluminium     214
  Plastics      84
  Epoxy resin   140
  Tin           230
  Lead          54
  Nickel        340
  Silver        1570
  Gold          84000
  ------------- ---------------------------------------

# Life cycle assessment (LCA)

As mentioned there are not many studies on LCA of nanotechnology and
much information has to be understood from extrapolation of experiences
from MEMS and micro manufacturing.

In the micro world LCA has predominantly been used in the
Micro-Electro-Mechanical Systems (MEMS) sector. The rapid development of
technologies and limited availability of data makes full blown LCAs
difficult and rather quickly outdated. An example is the manufacture of
a PC for which the energy requirement in the late 1980's were app. 2150
kWh whereas in the late 90's efficiency were improved and only 535 kWh
were necessary [^11] .

Using old data could result in erroneous results. Looking at the overall
environmental impact this fourfold increase in efficiency has been
overcompensated by an increase in number of sold computers from app. 21
mio to more than 150 mio [^12] causing an overall increase in
environmental impact. This is often referred to as a rebound effect. For
the development of cell phones, the same authors conclude that life
cycle impacts vary significantly from one product generation to the
next; hence generic product life cycle data should incorporate a
"technology development factor" for main parameters.

A major trend is that shrinking product dimensions raise production
environment requirements to prevent polluting the product. It involves
energy intensive heating, ventilation and air conditioning systems.
Clean room of class 10.000 for example requires app. 2280 kWh/m2∙a
whereas a class 100 requires 8440 kWh/m2∙a. The same increase of
requirements is relevant for supply materials like chemicals and gases.
The demand for higher purity levels implies more technical effort for
chemical purification, e.g. additional energy consumption and possibly
more waste. Most purification technologies are highly energy intensive,
e.g. all distillation processes, which are often used in wet chemical
purification, account in total for about 7 % of energy consumption of
the U.S. chemical industry [^13] . Chemicals used in large volumes in
semiconductor industry are hydrofluoric acid (HF), hydrogen peroxide
(H2O2) and ammonium hydroxide (NH4OH). These materials are used in final
cleaning processes and require XLSI grades (0.1 ppb). Sulphuric acid is
also used in large amounts, but it is a less critical chemical and
mainly requires an SLSI level purity [^14] .

Micromanufacturing of other types of products also puts higher
requirements on the quality and purity of the materials, e.g. a smaller
grain size in metals because of the smaller dimensions of the final
product. Additionally, a considerable amount of waste is produced. For
example, up to 99% of the material used for microinjection moulding of a
component may be waste since big runner are necessary for handling and
assembly. However, recycling of this waste may not be possible due to
requirements to and reduction of the material strength [^15] .

Miniaturisation also cause new problems in electronics recycling.
Take-back will hardly be possible. If they are integrated into other
product they need to be compatible with the recycling of these products
(established recycling paths) [^16] .

The very small size and incorporation into many different types of
products including product with limited longevity suggests an increased
use of disposable systems is required.

## Life cycle assessment of nanotechnology

As mentioned previously only few LCA studies have until now been
performed for nanotechnological products. A two day workshop on LCA of
nanotechnological products concluded that the current ISO-standard on
LCA (14040) applies to nanotechnological products but also that some
development is necessary [^17] [^18]

The main issues are that:sometimes it cracks the nerve

-   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 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.

Some of the concerns regarding the assessment of toxicological impacts
is closely linked to the risk assessment of nanoparticles and have to
await knowledge building in this area. However, the most striking is the
need for knowledge and cases where LCA are applied in order to increase
understanding of nanotechnological systems -- what are the potential
environmental impacts? How do they differ between different types of
nanotechnologies? Where should focus be put in order to prevent
environmental impacts? Etc.

## Additional resources

-   Nanometer societal assessment of
    nanotechnological applications prior to market release.

# Contributors to this page

This material is based on notes by

-   Stig Irving Olsen, Department of Manufacturing Engineering and
    Management, Building 424, NanoDTU Environment, Technical University
    of Denmark

and also by

-   Steffen Foss Hansen, Rikke Friis Rasmussen, Sara Nørgaard Sørensen,
    Anders Baun. Institute of Environment & Resources, Building 113,
    NanoDTU Environment, Technical University of Denmark
-   Kristian Mølhave, Dept. of Micro and Nanotechnology - DTU -
    www.mic.dtu.dk

# References

See also notes on editing this book
Nanotechnology/About#How_to_contribute.

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[^1]: Lloyd, S. M.; Lave, L. B.; Matthews, H. S. Life Cycle Benefits of
    Using Nanotechnology To Stabilize Platinum-Group Metal Particles in
    Automotive Catalysts. Environ. Sci. Technol. 2005, 39 (5),
    1384-1392.

[^2]: Lloyd, S. M.; Lave, L. B. Life Cycle Economic and Environmental
    Implications of Using Nanocomposites in Automobiles. Environ. Sci.
    Technol. 2003, 37 (15), 3458-3466.

[^3]: Steinfeldt, M.; Petschow, U.; Haum, R.; von Gleich, A.
    Nanotechnology and Sustainability. Discussion paper of the IÖW
    65/04; IÖW: 04.

[^4]: Helland A, Kastenholz H, Development of nanotechnology in light of
    sustainability, J Clean Prod (2007),
    <doi:10.1016/j.jclepro.2007.04.006>

[^5]: The Royal Society & The Royal Academy of Engineering Nanoscience
    and nanotechnologies: opportunities and uncertainties; The Royal
    Society: London, Jul, 04

[^6]: U.S.EPA U.S. Environmental Protection Agency Nanotechnology White
    Paper;EPA 100/B-07/001; Science Policy Council U.S. Environmental
    Protection Agency: Washington, DC, Feb, 07.

[^7]: Schmidt, K.: Green Nanotechnology: It\'s easier than you think.
    Woodrow Wilson International Center for Scholars. PEN 8 April 2007

[^8]: Klöpffer, W., Curran, MA., Frankl, P., Heijungs, R., Köhler, A.,
    Olsen, SI.: Nanotechnology and Life Cycle Assessment. A Systems
    Approach to Nanotechnology and the Environment. March 2007.
    Synthesis of Results Obtained at a Workshop in Washington, DC 2--3
    October 2006.

[^9]: Dillon AC, Nelson BP, Zhao Y, Kim Y-H, Tracy CE and Zhang SB:
    Importance of Turning to Renewable Energy Resources with Hydrogen as
    a Promising Candidate and on-board Storage a Critical Barrier.
    Mater. Res. Soc. Symp. Proc. Vol. 895, 2006

[^10]: Kuehr, R.; Williams, E. Computers and the environment; Kluwer
    Academic Publishers: Dordrecht, Boston, London, 2003.

[^11]: Schischke, K.; Griese, H. Is small green? Life Cycle Aspects of
    Technology Trends in Microelectronicss and Microsystems.
    <http://www>. lcacenter. org/InLCA2004/papers/Schischke_K\_paper.
    pdf 2004

[^12]:

[^13]: Plepys, A. The environmental impacts of electronics. Going beyond
    the walls of semiconductor fabs. IEEE: 2004; pp 159-165.

[^14]: Plepys, A. The environmental impacts of electronics. Going beyond
    the walls of semiconductor fabs. IEEE: 2004; pp 159-165.

[^15]: Sarasua, J. R.; Pouyet, J. Recycling effects on microstructure
    and mechanical behaviour of PEEK short carbon-fibre composites.
    Journal of Materials Science 1997, 32, 533-536.

[^16]:

[^17]:

[^18]: Something funny is happening with ref klöpffer3b
