DEVELOPMENT OF STANDARDIZED APPROACHES FOR THE RISK ASSESSMENT OF NANOMATERIALS
Julian S. Taurozzi
The assessment of potential risks associated with engineered nanomaterials (ENMs) requires the evaluation of ENMs in relevant matrices (e.g., cell culture media). For ENMs in dry powder form, the test material must first be dispersed in the test medium. The widespread use of ultrasonic treatment during the dispersion process has been inconsistently applied across laboratories, and the lack of process standardization contributes to the observed variability. The present work addresses the need for transferable dispersion and measurement protocols for powdered ENMs in relevant media. We discuss the effects of process parameters and medium composition on the dispersion and stability of ENMs. Results presented here will focus on nanoscale TiO2 in aqueous, biological and environmental media. Under optimized conditions, reproducible and stable nanoscale dispersions in the respective media are obtained. These results will be incorporated in NIST special publications.