SNWG Submits Comments on NIOSH Draft CIB on Silver Nanomaterials
On April 18, 2016, the Silver Nanotechnology Working Group (SNWG) submitted comments on the National Institute for Occupational Safety and Health’s (NIOSH) draft NIOSH Current Intelligence Bulletin: Health Effects of Occupational Exposure to Silver Nanomaterials. The draft Current Intelligence Bulletin (CIB) includes a review and assessment of the currently available scientific literature on the toxicological effects of exposure to silver nanoparticles in experimental animal and cellular systems, and on the occupational exposures to silver dust and fume and the associated health effects. According to the draft CIB, “[a]lthough the experimental animal and cellular studies are useful for showing potential risks from exposure to silver nanomaterials, NIOSH considers the currently available data to be too limited to develop a [recommended exposure limit (REL)] for silver that is specific to particle size.” Instead, NIOSH recommends that effective risk management control practices be implemented so that worker exposures to silver nanomaterials do not exceed the NIOSH REL of ten micrograms per cubic meter (μg/m3) (eight-hour time-weighted average) for silver metal dust, fume, and soluble compounds, measured as a total airborne mass concentration. The SNWG states that, in general, it agrees with NIOSH’s recommendation and the evidence upon which the recommendation is based. The SNWG “recognizes the uncertainties that NIOSH has concerning the current data on nanosilver particles, but continues to maintain that the toxicity of nanosilver is not significantly different from bulk or dissolved silver (colloidal silver).” The SNWG states that it “confirms NIOSH’s recommendation that if companies manufacturing and making use of nanosilver particles implement effective risk management control practices so that worker exposures to all forms of silver, including silver nanomaterials,” do not exceed the NIOSH REL for silver metal dust, fume, and soluble compounds measured as a total airborne mass concentration, “their workers will be more than adequately protected from any potential harmful exposures to all forms of silver, including nanosilver.” Regarding the research needs discussed in Section 8 of the draft CIB, the SNWG states that one of its functions is to identify, gather, and consolidate industry data in an anonymous manner to protect confidential business information. If NIOSH needs such a mechanism to obtain any needed data, the SNWG has offered to serve in such a capacity.