What is it? Nanotechnology is the science of coaxing unique properties and benefits from matter less than 100 nanometers. One nanometer equals one-billionth of a meter, or 1/10,000 the width of a human hair.

Benefits: At the nanoscale level, some matter exhibits special properties in relation to its size, including greater surface area, electrical conductivity and reactions to light. Products that contain nanotechnology include smaller, longer-lasting batteries, stickier adhesives, energy-efficient light bulbs and microchips that can store more data.

Risks: Studies show that certain nanomaterials could be harmful. Carbon nanotubes, which resemble asbestos fibers, cause lung inflammation, while nano-sized metals such as silver and elements such as carbon can rapidly travel to the brain through inhalation. Scientists are also not sure how humans and the environment react to nanomaterials over the long term.