On August 1, 2012, the U.S. Environmental Protection Agency (EPA) posted a final report entitled Nanomaterial Case Study: Nanoscale Silver in Disinfectant Spray, which EPA states “is intended to be used as part of a process to identify what is known and, more importantly, what is not yet known that could be of value in assessing the broad implications of certain nanomaterials.” According to EPA, “[t]he complex properties of various nanomaterials make evaluating them in the abstract or with generalizations difficult if not impossible.” EPA notes that the case study does not represent a completed, or even preliminary, assessment of nanosilver. Instead, it and other similar case studies are intended to support research planning efforts for nanomaterials. The case study is organized around the comprehensive environmental assessment (CEA) framework, which structures available information pertaining to the product lifecycle, transport, transformation and fate processes in environmental media, exposure-dose in receptors, and potential impacts in these receptors. If information is available, the case study also includes other direct and indirect ramifications of both primary and secondary substances or stressors associated with a nanomaterial. Through a structured collective judgment method, expert stakeholders used EPA’s draft case study to identify and prioritize research gaps that could inform future assessments and risk management efforts. Some of the research gaps pertain to nanosilver in disinfectant spray; others to nanosilver irrespective of its application, and still others to nanomaterials in general.