EPA has announced that it seeks public comments on a nanoscale silver case study and an approach to analyzing its risks. Titled “Nanomaterial Case Study: Nanoscale Silver in Disinfectant Spray,” the study poses questions about such issues as (i) the physicochemical properties of nanoscale silver; (ii) analytic techniques to study it; (iii) ways to calculate worldwide and domestic nanoscale silver production; (iv) whether disinfectant sprays containing nanoscale silver could enter the environment; (v) whether sewage sludge and wastewater treatment technologies would remove nanoscale silver; (vi) whether particular species or human populations have greater exposure to nanoscale silver; and (vii) the extent to which particle properties, such as size, shape, chemical composition, and surface treatments, determine biological responses of nanoscale silver. EPA will accept comments through September 27, 2010.