EPA 100/B-07/001 | February 2007 www.epa.gov/osa Nanotechnology White Paper Office of the Science Advisor Science Policy Council EPA 100/B-07/001 February 2007 U.S. Environmental Protection Agency Nanotechnology White Paper Prepared for the U.S. Environmental Protection Agency by members of the Nanotechnology Workgroup, a group of EPA’s Science Policy Council Science Policy Council U.S. Environmental Protection Agency Washington, DC 20460 ii EPA Nanotechnology White Paper DISCLAIMER This document has been reviewed in accordance with U.S. Environmental Protection Agency policy and approved for publication and distribution. Mention of trade names or commercial products does not constitute endorsement of recommendation for use. Notwithstanding any use of mandatory language such as "must" and "require" in this document with regard to or to reflect scientific practices, this document does not and should not be construed to create any legal rights or requirements. Cover Images: Left: Computer images of various forms of carbon nanotubes. Images courtesy of Center for Nanoscale Materials, Argonne National Laboratory Right: Computer image of a dendrimer. Image courtesy of Dendritic NanoTechnologies, Inc. Title Page Image: Computer image of a C-60 Fullerene. Laurence Libelo, U.S. EPA. iii EPA Nanotechnology White Paper Nanotechnology White Paper Workgroup Co-Chairs Jeff Morris Jim Willis Office of Research and Development Office of Prevention, Pesticides and Toxic Substances Science Policy Council Staff External Coordination Steve Lingle, ORD Dennis Utterback, ORD EPA Research Strategy Barbara Karn, ORD Nora Savage, ORD Risk Assessment Phil Sayre, OPPTS Physical-Chemical Properties Tracy Williamson, OPPTS Health Effects Deborah Burgin, OEI Kevin Dreher, ORD Kathryn Gallagher Office of the Science Advisor Subgroup Co-Chairs Ecological Effects Anne Fairbrother, ORD Tala Henry, OPPTS Vince Nabholz, OPPTS Human Exposures Scott Prothero, OPPT Environmental Fate Bob Boethling, OPPTS Laurence Libelo, OPPTS John Scalera, OEI Environmental Detection and Analysis John Scalera, OEI Richard Zepp, ORD Statutes, Regulations, and Policies Jim Alwood, OPPT Risk Management Flora Chow, OPPT Converging Technologies Nora Savage, ORD Pollution Prevention Walter Schoepf, Region 2 Sustainability and Society Diana Bauer, ORD Michael Brody, OCFO Public Communications and Outreach Anita Street, ORD iv EPA Nanotechnology White Paper Workgroup Members Suzanne Ackerman, OPA Kent Anapolle, OPPTS Fred Arnold, OPPTS Ayaad Assaad, OPPTS Dan Axelrad, OPEI John Bartlett, OPPTS Sarah Bauer, ORD Norman Birchfield, OSA John Blouin, OPPT Jim Blough, Region 5 Pat Bonner, OPEI William Boyes, ORD Gordon Cash, OPPTS Gilbert Castellanos, OIA Tai-Ming Chang, Region 3 Paul Cough, OIA Lynn Delpire, OPPTS John Diamante, OIA Christine Dibble, OPA Jeremiah Duncan, AAAS fellow, OPPTS Thomas Forbes, OEI Conrad Flessner, OPPTS Jack Fowle, ORD Elisabeth Freed, OECA Sarah Furtak, OW Hend Galal-Gorchev, OW David Giamporcaro, OPPTS Michael Gill, ORD liaison for Region 9 Collette Hodes, OPPTS Gene Jablonowski, Region 5 Lee Hofman, OSWER Joe Jarvis, ORD Y’Vonne Jones-Brown, OPPTS Edna Kapust, OPPTS Nagu Keshava, ORD David Lai, OPPTS Skip Laitner, OAR Warren Layne, Region 5 Do Young Lee, OPPTS Virginia Lee, OPPTS Monique Lester, OARM, on detail to OIA Michael Lewandowski, ORD Bill Linak, ORD David Lynch, OPPTS Tanya Maslak, OSA intern Paul Matthai, OPPT Carl Mazza, OAR Nhan Nguyen, OPPTS Carlos Nunez, ORD Onyemaechi Nweke, OPEI Marti Otto, OSWER Manisha Patel, OGC Steve Potts, OW Mary Reiley, OW Mary Ross, OAR Bill Russo, ORD Mavis Sanders, OEI Bernie Schorle, Region 5 Paul Solomon, ORD Timothy Taylor, OSWER Maggie Theroux-Fieldsteel, Region 1 Stephanie Thornton, OW Alan Van Arsdale, Region 1 William Wallace, ORD Barb Walton, ORD v EPA Nanotechnology White Paper Table of Contents FOREWORD ................................................................................................................................................... VIII ACKNOWLEDGMENTS.................................................................................................................................. IX ACRONYMS.........................................................................................................................................................X EXECUTIVE SUMMARY ...................................................................................................................................1 1.0 INTRODUCTION ...........................................................................................................................................4 1.1 PURPOSE ........................................................................................................................................................4 1.2 NANOTECHNOLOGY DEFINED ........................................................................................................................5 1.3 WHY NANOTECHNOLOGY IS IMPORTANT TO EPA .......................................................................................13 1.4 NATIONAL AND INTERNATIONAL CONTEXT.................................................................................................14 1.5 WHAT EPA IS DOING WITH RESPECT TO NANOTECHNOLOGY .....................................................................18 1.6 OPPORTUNITIES AND CHALLENGES..............................................................................................................21 2.0 ENVIRONMENTAL BENEFITS OF NANOTECHNOLOGY ................................................................22 2.1 INTRODUCTION ............................................................................................................................................22 2.2 BENEFITS THROUGH ENVIRONMENTAL TECHNOLOGY APPLICATIONS.........................................................22 2.3 BENEFITS THROUGH OTHER APPLICATIONS THAT SUPPORT SUSTAINABILITY .............................................24 3.0 RISK ASSESSMENT OF NANOMATERIALS.........................................................................................29 3.1 INTRODUCTION ............................................................................................................................................29 3.2 CHEMICAL IDENTIFICATION AND CHARACTERIZATION OF NANOMATERIALS ..............................................31 3.3 ENVIRONMENTAL FATE OF NANOMATERIALS..............................................................................................32 3.4 ENVIRONMENTAL DETECTION AND ANALYSIS OF NANOMATERIALS ...........................................................40 3.5 HUMAN EXPOSURES AND THEIR MEASUREMENT AND CONTROL ................................................................42 3.6 HUMAN HEALTH EFFECTS OF NANOMATERIALS..........................................................................................52 3.7 ECOLOGICAL EFFECTS OF NANOMATERIALS................................................................................................58 4.0 RESPONSIBLE DEVELOPMENT .............................................................................................................63 4.1 RESPONSIBLE DEVELOPMENT OF NANOSCALE MATERIALS .........................................................................63 4.2 PROGRAM AREAS.........................................................................................................................................65 4.3 ENVIRONMENTAL STEWARDSHIP .................................................................................................................68 5.0 EPA’S RESEARCH NEEDS FOR NANOMATERIALS ..........................................................................70 5.1 RESEARCH NEEDS FOR ENVIRONMENTAL APPLICATIONS ............................................................................70 5.2 RESEARCH NEEDS FOR RISK ASSESSMENT...................................................................................................72 6.0 RECOMMENDATIONS ..............................................................................................................................82 6.1 RESEARCH RECOMMENDATIONS FOR ENVIRONMENTAL APPLICATIONS ......................................................82 6.2 RESEARCH RECOMMENDATIONS FOR RISK ASSESSMENT.............................................................................83 6.3 RECOMMENDATIONS FOR POLLUTION PREVENTION AND ENVIRONMENTAL STEWARDSHIP.........................89 6.4 RECOMMENDATIONS FOR COLLABORATIONS...............................................................................................90 6.5 RECOMMENDATION TO CONVENE AN INTRA-AGENCY WORKGROUP...........................................................91 6.6 RECOMMENDATION FOR TRAINING..............................................................................................................91 6.7 SUMMARY OF RECOMMENDATIONS .............................................................................................................92 7.0 REFERENCES ..............................................................................................................................................93 APPENDIX A: GLOSSARY OF NANOTECHNOLOGY TERMS .............................................................107 APPENDIX B: PRINCIPLES OF ENVIRONMENTAL STEWARDSHIP BEHAVIOR..........................110 APPENDIX C: EPA’S NANOTECHNOLOGY RESEARCH FRAMEWORK..........................................111 APPENDIX D: EPA STAR GRANTS FOR NANOTECHNOLOGY ..........................................................113 vi EPA Nanotechnology White Paper APPENDIX E: LIST OF NANOTECHNOLOGY WHITE PAPER EXTERNAL PEER REVIEWERS AND THEIR AFFILIATIONS ..................................................................................................................................119 vii EPA Nanotechnology White Paper Table of Figures FIGURE 1. DIAGRAM INDICATING RELATIVE SCALE OF NANOSIZED OBJECTS......................................................6 FIGURE 2. GALLIUM PHOSPHIDE (GAP) NANOTREES............................................................................................7 FIGURE 3. COMPUTER IMAGE OF A C-60 FULLERENE...........................................................................................8 FIGURE 4. COMPUTER IMAGES OF VARIOUS FORMS OF CARBON NANOTUBES. ....................................................8 FIGURE 5. “FOREST” OF ALIGNED CARBON NANOTUBES.......................................................................................8 FIGURE 6. ZINC OXIDE NANOSTRUCTURE SYNTHESIZED BY A VAPOR-SOLID PROCESS........................................9 FIGURE 7. COMPUTER IMAGE OF AGALLIUM ARSENIDE QUANTUM DOT OF 465 ATOMS.....................................9 FIGURE 8. COMPUTER IMAGE OF GENERATIONS OF A DENDRIMER......................................................................9 FIGURE 9. COMPUTER IMAGE OF A NANO-BIO COMPOSITE. ...............................................................................10 FIGURE 10. PROJECTED STAGES OF NANOTECHNOLOGY DEVELOPMENT..........................................................13 FIGURE 11. FEDERAL SOURCES TO INFORM EPA’S NANOTECHNOLOGY ACTIVITIES.......................................15 FIGURE 12. NNI NSET SUBCOMMITTEE STRUCTURE..........................................................................................16 FIGURE 13. NANOSCALE ZERO-VALENT IRON ENCAPSULATED IN AN EMULSION DROPLET................................22 FIGURE 14. PIEZORESISTIVE CANTILEVER SENSOR..............................................................................................24 FIGURE 15. EPA’S RISK ASSESSMENT APPROACH...............................................................................................29 FIGURE 16. LIFE CYCLE PERSPECTIVE TO RISK ASSESSMENT ...........................................................................30 FIGURE 17. TRANSMISSION ELECTRON MICROSCOPE (TEM) IMAGE OF AEROSOL-GENERATED TIO2 NANOPARTICLES.....................................................................................................................................................32 FIGURE 18. ZINC OXIDE NANOSTRUCTURES SYNTHESIZED BY A VAPOR-SOLID PROCESS...................................35 FIGURE 19. SEM OF A SCANNING GATE PROBE.....................................................................................................42 FIGURE 20. PARTICLE TOXICOLOGY CITATIONS..................................................................................................53 FIGURE 21. FLUORESCENT NANOPARTICLES IN WATER FLEA (DAPHNIA MAGNA)..............................................60 FIGURE 22. EPA OFFICE ROLES ...........................................................................................................................64 Table of Tables TABLE 1. EXAMPLES OF PRODUCTS THAT USE NANOTECHNOLOGY AND NANOMATERIALS ............................11 TABLE 2. OUTCOMES FOR SUSTAINABLE USE OF MAJOR RESOURCES AND RESOURCE SYSTEMS ...................25 TABLE 3. POTENTIAL U.S. ENERGY SAVINGS FROM EIGHT NANOTECHNOLOGY APPLICATIONS ....................26 TABLE 4. POTENTIAL SOURCES OF OCCUPATIONAL EXPOSURE FOR VARIOUS SYNTHESIS METHODS ............44 TABLE 5. EXAMPLES OF POTENTIAL SOURCES OF GENERAL POPULATION AND / OR CONSUMER EXPOSURE FOR SEVERAL PRODUCT TYPES ...................................................................................................................................45 TABLE 6. SUMMARY OF WORKGROUP RECOMMENDATIONS REGARDING NANOMATERIALS...........................92 viii EPA Nanotechnology White Paper FOREWORD Nanotechnology presents opportunities to create new and better products. It also has the potential to improve assessment, management, and prevention of environmental risks. However, there are unanswered questions about the impacts of nanomaterials and nanoproducts on human health and the environment. In December 2004, EPA’s Science Policy Council (SPC) formed a cross-Agency Nanotechnology Workgroup to develop a white paper examining potential environmental applications and implications of nanotechnology. This document describes the issues that EPA should consider to ensure that society benefits from advances in environmental protection that nanotechnology may offer, and to understand and address any potential risks from environmental exposure to nanomaterials. Nanotechnology will have an impact across EPA. Agency managers and staff are working together to develop an approach to nanotechnology that is forward thinking and informs the risk assessment and risk management activities in our program and regional offices. This document is intended to support that cross-Agency effort. We would like to acknowledge and thank the Nanotechnology Workgroup subgroup co­ chairs and members and for their work in developing this document. We would especially like to acknowledge the Workgroup co-chairs Jim Willis and Jeff Morris for leading the workgroup and document development. We also thank SPC staff task lead Kathryn Gallagher, as well as Jim Alwood, Dennis Utterback, and Jeremiah Duncan for their efforts in assembling and refining the document. It is with pleasure that we provide the EPA Nanotechnology White Paper to promote the use of this new, exciting technology in a manner that protects human health and the environment. William H. Benson Charles M. Auer Acting Chief Scientist Director, Office of Pollution Office of the Science Advisor Prevention and Toxics