On October 19, 2018, the U.S. Environmental Protection Agency (EPA) posted the Final Work Plan (FWP) for the nanosilver registration review process under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). The FWP explains what the Office of Pesticide Programs (OPP) “knows about nanosilver generally, highlighting anticipated data and assessment needs for each unique nanosilver chemistry, identifying the types of information that would be especially useful to the Agency in conducting the review, and providing an anticipated timeline for completing review of the nanosilver case.” According to the FWP, EPA has identified the following use patterns to date: swimming pool/spa treatments; and material preservative products for coatings, textiles, and plastics. The FWP states that people may be exposed to nanosilver through inhalation and dermal exposures while applying the products to swimming pools and from incidental oral exposures during swimming. Further exposures may come from material preservative uses either while applying or from nanosilver that leaches out when textiles and plastics are washed. Nontarget organisms can be exposed when swimming pool water is released or when nanosilver used as a material preservative leaches.
According to the FWP, EPA “anticipates the need to require generation and submission of human health hazard and exposure data and to conduct a human health risk assessment for nanosilver during registration review.” The FWP states that EPA plans to conduct an environmental risk assessment for the nanosilver uses, “particularly focusing on materials preservative uses, such as plastics and textiles if the particular nanosilver chemistries are shown to leach, and swimming pool uses.” Any of the other use patterns may also be subject to ecological assessment if the fate and product chemistry profiles indicate the potential for environmental exposures. According to the FWP, the risk assessment integrates the environmental fate and effects data to determine if any uses pose risks to nontarget organisms. Potential risks to fish, aquatic invertebrates, aquatic plants, and birds and mammals will be assessed after the data gaps specified in the FWP are satisfied and the relevant data are available.
EPA invites any label amendments that could be considered to eliminate the anticipated need to require certain data, reduce the possibility that EPA’s planned risk assessments overestimate risk due to reliance on conservative assumptions, and/or improve label clarity. EPA anticipates issuing in 2018 a DCI requiring the data set out in Table 7 of the FWP, “Studies Anticipated as Needed for Nanosilver Registration Review.”