Final answer:
The FDA regulates nanotechnology based on the size of nanomaterials to address safety and efficacy concerns.
Step-by-step explanation:
The current regulation of nanotechnology by the FDA is primarily based on the size of the nanomaterials involved. Nanotechnology refers to the development of very small products and components, typically between 1 and 100 nanometers in size. These nanomaterials have unique properties and applications, which require careful regulation to ensure their safety and efficacy. By regulating based on size, the FDA can address the specific challenges and risks associated with nanotechnology.