Earlier this month the National Institute for Occupational Safety and Health (NIOSH) posted a fact sheet sponsored by the American Industrial Hygiene Association (AIHA) Nanotechnology Working Group entitled Personal Protective Equipment for Engineered Nanoparticles.  The fact sheet defines engineered nanoparticles as intentionally produced solid particles with at least one dimension in the size range of approximately 1 to 100 nanometers.  According to the fact sheet, “[r]ecent studies and experience support the fact that traditional exposure control approaches can also work for intentionally produced nanoparticles when selected and implemented as part of a comprehensive occupational safety and health plan.”  The fact sheet recommends managing exposure risks by following the industrial hygiene hierarchy of controls approach.  For best results, exposure prevention and control measures should be considered early in the planning of experiments, development of products, and design of manufacturing processes, so that appropriate controls can be planned and selected.  The fact sheet describes personal protective equipment (PPE) as “the last line of defense” and states that it should be used when other controls are not feasible or not effective in reducing exposures to acceptable levels, or while controls are in the process of being implemented.  According to the fact sheet, “PPE may also be used to supplement other control measures for added precaution, and should be used as part of a comprehensive workplace PPE program.”