This chapter provides a review of the state of science surrounding nanomaterial exposure, explores the methods and data available for nanomaterial releases from products across their life cycle, considers what tools are used to detect and quantify nanomaterial exposure, and discusses the future steps to understand nanomaterial exposure. It presents critical data gaps and methods that could advance nanomaterial exposure analysis in the environment. The physicochemical properties of nanomaterials allow for them to have transformative benefits to individuals and society through applications including but not limited to enhanced food products, improved energy storage, antimicrobial fabrics, and water purification. The chapter also provides a general review of the state of science in nanomaterial exposure, specifically on the current trends in engineered nanomaterials (ENM) exposure, dosimetry challenges, and concentration levels of concern. The truth is that the physicochemical properties of ENMs make them highly reactive in environmental systems, resulting in transformations that will greatly influence their behavior.