Assessing nanoparticle risk poses prodigious challenges

Risk assessment is used both formally and informally to estimate the likelihood of an adverse event occurring, for example, as a consequence of exposure to a hazardous chemical, drug, or other agent. Formal risk assessments in government regulatory agencies have a long history of practice. The precision with which risk can be estimated is inevitably constrained, however, by uncertainties arising from the lack of pertinent data. Developing accurate risk assessments for nanoparticles and nanoparticle‐containing products may present further challenges because of the unique properties of the particles, uncertainties about their composition and the populations exposed to them, and how these may change throughout the particle's life cycle. This review introduces the evolving practice of risk assessment followed by some of the uncertainties that need to be addressed to improve our understanding of nanoparticle risks. Given the clarion call for life‐cycle assessments of nanoparticles, an unprecedented degree of national and international coordination between scientific organizations, regulatory agencies, and stakeholders will be required to achieve this goal. WIREs Nanomed Nanobiotechnol 2013, 5:374–387. doi: 10.1002/wnan.1216 This article is a U.S. Government work, and as such, is in the public domain in the United States of America. Disclaimer: This manuscript has been reviewed by the National Health and Environmental Effects Research Laboratory and approved for publication. The approval does not signify that the contents reflect the views of the agency, nor does mention of trade names or commercial products constitute endorsement or recommendation for use. This article is categorized under: Toxicology and Regulatory Issues in Nanomedicine > Regulatory and Policy Issues in Nanomedicine Toxicology and Regulatory Issues in Nanomedicine > Toxicology of Nanomaterials