The term "nanotechnology" is applied to everthing from micro-robotic self-replicating assemblers to Docker's Stain Defender pants. It's frequently becoming a marketing buzzword, but the truth is that manufacturers are in fact using increasing amounts of materials whose components measure 100 nanometers or less (a human hair is about 1,000 times wider).
These nanomaterials have new and useful properties, but the fact is that we don't really know what their toxic effects might be. For example, what would happen if you inhaled a cloud of tiny carbon nanotubes? The materials are so new we can't yet characterize their long term effects.
This very problem was addressed today in a report released today by the International Life Sciences Institute. The report, funded by the EPA, suggests a framework for characterizing these materials and determining their toxicity.