The Environmental Protection Agency (EPA) has opened the investigation of nanoscale titanium dioxide in water treatment and topical sunscreen with a draft document and a call for public comment. Engineered nanoscale materials (nanomaterials), according to the EPA, are conventionally defined as having at least one dimension between 1 and 100 nanometers (nm) and unique properties that arise from their small size. Like all technological developments, nanomaterials offer the potential for both benefits and risks. For an overview of nanomaterials in sun care, view the November 2008 column by Mindy Goldstein, "Nanomaterials in Personal Care: Opportunities and Safety Considerations."
The agency's document, ‘‘Nanomaterial Case Studies: Nanoscale Titanium Dioxide in Water Treatment and Topical Sunscreen,’’ is a starting point to identify what is known and what needs to be known about selected nanomaterial applications—in this case, for nanoscale titanium dioxide (nano-TiO2)—to assess their potential ecological and health implications.
Thus, this document focuses on two specific uses of nano-TiO2, as a drinking water treatment and as topical sunscreen. These ‘‘case studies’’ do not represent completed or even preliminary assessments; rather, they present the structure for identifying and prioritizing research needed to support future assessments. The case studies follow the comprehensive environmental assessment (CEA) approach, which combines a product life-cycle framework with the risk assessment paradigm. In essence, risk assessment relates exposure and effects information for a given substance or stressor, and CEA expands on this paradigm by including life-cycle stages and considering both indirect and direct ramifications of a substance or stressor.
The draft document was posted for public comment on July 31, 2009, for 45 days, and technical comments must be received by the EPA in writing by Sept. 14, 2009. The document was prepared by the National Center for Environmental Assessment within EPA’s Office of R&D.
EPA is releasing this draft document solely for the purpose of pre-dissemination peer review under applicable information quality guidelines. When finalizing the draft document, EPA intends to consider any public comments that EPA receives in accordance with this notice.