Engineered nanoparticles (ENP) are being used in many applications including consumer products. There are many different means by which ENPs may be incorporated into these products (freely- dispersed, embedded, reactive or passive) which can impact the potential for consumer exposure to ENPs. This study was motivated by the desire to better understand inhalation exposure to ENPs, and this report addresses airborne ENPs that could affect indoor air quality (IAQ). Occupant exposure to airborne nanoparticles can be characterized by indoor airflow and contaminant transport analysis models. The U.S. Consumer Product Safety Commission (CPSC) is working with the National Institute of Standards and Technology (NIST) to develop modeling tools to enable evaluation of consumer exposure to airborne ENPs in the built environment. NIST has developed two tools, the first is an online tool that provides estimates of indoor exposure to airborne particles. This first tool, referred to as the single-size particle tool, is based on the NIST multizone modeling software, CONTAM, and demonstrates some of the capabilities that an aerosol exposure assessment tool should entail. The second tool, referred to as the size-resolved tool, includes additional physical models that account for the properties of nanoparticles that may impact their transport within the built environment including some beyond those that CONTAM is currently capable of modeling, e.g., coagulation. This report describes the development and application of these two analysis tools that could provide the basis of modeling consumer exposure to ENPs for future development.
Technical Note (NIST TN) - 2004
consumer products, modeling, nanoparticle, validation