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Particle and Fibre Toxicology

Open Access

Principles for characterizing the potential human health effects from exposure to nanomaterials: elements of a screening strategy

  • Günter Oberdörster1,
  • Andrew Maynard2,
  • Ken Donaldson3,
  • Vincent Castranova4,
  • Julie Fitzpatrick5Email author,
  • Kevin Ausman6,
  • Janet Carter7,
  • Barbara Karn8, 9,
  • Wolfgang Kreyling10,
  • David Lai11,
  • Stephen Olin5,
  • Nancy Monteiro-Riviere12,
  • David Warheit13,
  • Hong Yang14 and
  • A report from the ILSI Research Foundation/Risk Science Institute Nanomaterial Toxicity Screening Working Group
Particle and Fibre Toxicology20052:8

Received: 03 October 2005

Accepted: 06 October 2005

Published: 06 October 2005

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Archived Comments

  1. Comments on Oberdorster et al.

    25 January 2006

    Bill Gulledge, ACC Nanotechnology Panel


    (Oberdorster et al., 2005)

    23 December 2005

    Dear Sir:

    The Nanotechnology Panel of the American Chemistry Council submits the following comments on the Oberdorster et al. paper on a screening strategy for nanomaterials.

    “Principles for characterizing the potential human health effects from exposure to nanomaterials: elements of a screening strategy” (Oberdorster et al. (2005) provides a valuable contribution in describing principles of a research strategy for evaluating human health aspects of nanoscale materials, but has limitations in describing a means to evaluate environmental, health and safety risks. Although screening and characterization could be helpful, the “principles” would be more usefully applied to an existing testing framework (e.g. globally harmonized OECD guideline) than developing specific hypothesis driven tests.

    Specific comments are noted below.

    • There is an over emphasis on in vitro methods. Although these may be of some use in hazard identification, exposure-relevant tests by a suitable route, with an array of standard end-points would be of more value as a basis for decisions regarding risk. Interpretation of in vitro studies would likely require validation by comparison with in vivo data. Globally harmonized test protocols (e.g. OECD and EPA OPPTS) are intended to evaluate a broad spectrum of potential effects, rather than addressing a specific hypothesis regarding the effects of a material. The principles described in the Oberdorster paper may be more usefully applied to enhance globally harmonized tests for test material characterization and evaluating potential end points of concern. In theory, globally harmonized tests could be applied to oral, inhalation and dermal exposure, though specific development may be needed to conduct a relevant exposure.

    • The recommendation that “independent characterizations of nanomaterials (beyond information provided by producers and suppliers) are carried out where possible" is inappropriate. Documented analysis (e.g. by GLP procedures) is acceptable to regulatory agencies for industrial and agricultural chemicals as well as drugs; a different standard would serve no purpose. Basic GLP test material characterization should be possible. We recognize challenges in that some innovative analytical methods may not be available as GLP procedures.

    • The importance of characterization is recognized, though some balance will be needed. Traditionally, test materials are characterized for identity, total purity, specific impurities above 0.1%, and stability. A suitable judgment about resources will be needed to determine the appropriate amount of characterization, particularly for a lower tiered study. Also, characterization in the body (versus test material and material in dosing vehicle), is beyond the scope of normal testing. These evaluations should be considered a research project or pharmacokinetic study, not a part of a routine study to evaluate effects.

    • Developing computational toxicology is a worthwhile long term objective, but it is limited in current applications for routine chemical EHS evaluation. There is insufficient validation of methods with nanoparticles to implement computational toxicology in the near to mid-term.

    The Oberdorster et al. report is an excellent starting point for the evaluation of potential health hazards of nano materials. Many recommendations by Oberdorster et al. have value in providing adjunctive information to that from validated study protocols. The report would have been more informative if it included the rationale for selecting the tests contained in Tiers 1 and 2 and provided an explanation for moving between Tiers. We believe that the preferred approach to consider for tiered testing is to rely on validated test methods with protocols established by the OECD.

    Competing interests

    None declared

Authors’ Affiliations

Department of Environmental Medicine, University of Rochester, Rochester, USA
Project on Emerging Nanotechnologies, Woodrow Wilson International Center for Scholars, Washington, USA
MRC/University of Edinburgh Centre for Inflammation Research, ELEGI Colt Laboratory Queen's Medical Research Institute, Edinburgh, UK
Pathology and Physiology Research Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, USA
Risk Science Institute, ILSI Research Foundation, International Life Sciences Institute, Washington, USA
Center for Biological and Environmental Nanotechnology, MS-63, P.O. Box 1892, Rice University, Houston, USA
Respiratory/Inhalation Toxicology, Central Product Safety, Procter & Gamble Company, Cincinnati, USA
Office of Research and Development, United States Environmental Protection Agency, Washington, USA
Project on Emerging Nanotechnologies, Woodrow Wilson International Center for Scholars, Washington, USA
Institute for Inhalation Biology & Focus Network: Aerosols and Health, GSF National Research Centre for Environment and Health, Neuherberg, Germany
Risk Assessment Division, Office of Pollution Prevention & Toxics, United States Environmental Protection Agency, 7403M, Washington, USA
Center for Chemical Toxicology and Research Pharmacokinetics, College of Veterinary Medicine, North Carolina State University, Raleigh, USA
DuPont Haskell Laboratory for Health and Environmental Sciences, Newark, USA
Department of Chemical Engineering, University of Rochester, Rochester, USA