What are the major challenges facing the NTP with regard to its nanotechnology safety assessment?
Prioritizing and obtaining materials to evaluate are major challenges for the NTP. Specific nanomaterials with the highest exposure potentials are not well known, making it difficult to identify the most important materials to study. Obtaining materials is also an impediment. In many cases, information about the nanoscale material is proprietary. Consequently, the NTP may be unable to study those materials that pose the highest potential exposure to humans. In other cases, the material may be available, but not in sufficient quantities to allow an adequate hazard evaluation, particularly regarding long-term, repeated exposure studies. Characterization of nanomaterials has proven to be more difficult than anticipated for several reasons. First, a standard nomenclature has not been developed. Second, biologists, physicists, and materials scientists working in this area often do not communicate effectively. In addition, an analytical infrastructure to allow characterization is not consist
