Respiratory Protection for Nanoparticles

A. Nanoparticles are very small (nearly atomic scale) with diameters less than 100 nm (<0.1 micron) in at least one dimension. Because of their small size, air sampling results indicating low mass concentrations actually contain greater numbers and larger surface area/unit mass of nanoparticles than for the same mass concentration of larger particles. Also, nanoparticles may be more biologically reactive than larger particles of similar chemical composition because of their smaller, more lung penetrating size, and their increased surface area dose.