NSF-EPA Workshop on Life Cycle Aspects of Nanoproducts, Nanostructured Materials,

and Nanomanufacturing: Problem Definitions, Data Gaps, and Research Needs

November 5-6, 2009

Chicago, IL

Why nano?

• An “enabling” technology with implications for energy, manufacturing, electronics, transportation, healthcare, pharmaceuticals, environmental control and purification, sensors and national security, chemical processing, and sustainable development

Why Life Cycle?

• An integrative methodology--life cycle analysis is a good way to understand the totality of environmental impacts and (most) of the benefits of nanotechnology, and where along the product chain these occur

• LCA allows for comparisons with conventional products that may be displaced in commerce

• LCA facilitates communication of risks and benefits to stakeholders and consumers

• LCA can help to prevent unnecessary regulation and to avoid “unintended consequences”

• Apply LCA near the beginning of the nanotech “revolution”, a rare opportunity

Previous workshop: Nanotechnology and Life Cycle Assessment

Washington DC October 2-3 2006

Major conclusions:

• Major efforts are needed to fully assess potential risks and environmental impacts of nanoproducts and materials

• All stages of the life cycle of nanoproducts should be assessed via LCA studies

• The main problem with LCA of nanomaterials and nanoproducts is the lack of data and understanding in certain areas

Previous workshop: Nanotechnology and Life Cycle Assessment

Washington DC October 2-3 2006

Major conclusions (continued):

• 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

• Uncertainty in LCA studies should be acknowledged and quantified

• 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

Goals of the this workshop

• Review existing research, assess the state of science, and identify gaps in the knowledge base regarding the life cycle of nanotechnological products and processes,

• Develop a critical understanding of combinations of nanostructured materials, their manufacturing processes, and resultant products that offer the greatest promise for improvements for society, as well as those that offer little promise or have a high probability of creating or worsening environmental hazards,

• Lay out research priorities to address the needs identified,

• Establish a pathway forward that could be pursued by relevant stakeholders on life cycle/nanotechnology research, and

• Explore the basis of a life cycle-based management framework for nanotechnological applications

Nano-based publications

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Topical Areas of Nanotech Life Cycle Publications

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ISO 14040:2006

Life Cycle Assessment Framework

Life Cycle Assessment Stages

Energy Requirements

0

11

2

3

4

5

6

7

EAF Steel Aluminum Poly Si Wafer Si Nanotubes Quantum dots

Material

Log (MJ/kg)

Energy requirements of several materials (adapted from Gutowski et al. 2007, and Sengul and Theis 2008).

1

2

3

4

5

6

Sources of nanomanufacturing impacts

• Low process yields

• Energy requirements

• Repeated processing, postprocessing, or reprocessing steps of a single product or batch during manufacturing

• Use of toxic/basic/acidic chemicals and organic solvents

• Strict purity requirements and less tolerance for contamination during processing (up to “nine nines”)

• High water consumptionSengul and Theis JIE, 2008.

Example: Elements used in semiconductors

Aqueous solubility of semiconductor synthetics

Sulfides, most oxides: abundant info

Binary selenides, tellurides: some info

Nitrides, phosphides, arsenides, stibnides, tertiary, quaternary, doped, magnetic: none

CdSe in aquatic environments

-15

-10

-5

0

5

10

15

20

25

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14

pH

pЄ

H2SeO3(aq)

HSeO3-

SeO3-2

HSeO4-

SeO4-2, Cd+2

CdSe(s)

Se(s)

O2

H2O

H2

H2O

Cd(OH)2(s)

Rain

Naturalwaters

SedimentsAndSoils

Intracellenvironment

Concluding remarks

• The ability to make and control very small structured materials has very large implications for human health, comfort and convenience, and economic well-being

• In comparison to basic nanoscience and the fabricaton of nanostructures, our understanding of environmental and life cycle behaviors of nanomanufacturing, nanomaterials, and nano-containing products exhibit exceptional lags

• Even so, it is probable that there will be sizable energy requirements, a suite of significant waste management problems, and unknown material supply and end-of-life concerns