Employees who use nanomaterials in research or production processes may be exposed to nanoparticles through inhalation, dermal contact, or ingestion, depending upon how employees use and handle them. Although the potential health effects of such exposure are not fully understood at this time, scientific studies indicate that at least some of these materials are biologically active, may readily penetrate intact human skin, and have produced toxicologic reactions in the lungs of exposed experimental animals.