ABSTRACT

This chapter discusses efforts toward categorizing nanomaterials for health and environmental risk assessment. Efforts in categorization for health and environmental risk assessment were initially developed for chemical substances before the advent of manufactured nanomaterials. Categorization of nanomaterials offers a way to group similar substances so that risk information from one substance can begin to be used to predict risk types for related but less studied substances. Grouping of nanomaterials for environmental risk assessment involves considering alternate exposure scenarios that impacts the physicochemical properties and life cycle parameters used for grouping criteria. A number of risk assessment approaches for the categorization of nanomaterials acknowledge an ultimate goal of grouping nanomaterials by physicochemical properties as they relate to hazards. Selecting the appropriate categorization scheme is a difficult challenge. The resultant categories must be useful to the taxonomist as well as the larger community that will use the scheme.