Nanomaterials encompass a wide range of substances based on the understanding and control of matter at the scale of nanometers-the equivalent of one-billionth of a meter. Nanomaterials are nanoscale materials or materials that contain nanoscale structures internally or on their surfaces. Nanomaterials are currently used in a wide variety of applications, including consumer products, health care, transportation, energy, and agriculture. While some nanomaterials can occur naturally, this report focuses on intentionally manufactured nanomaterials. Figure 1 illustrates the relative size of nanomaterials.