EPA Publishes Final Nanomaterial Case Study For Nanoscale Silver in Disinfectant Spray

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.

EPA Posts Summary of 2011 Nanomaterial Case Studies Workshop

On February 9, 2012, the U.S. Environmental Protection Agency (EPA) posted a summary report on its January 2011 workshop on nanoscale silver. The workshop was the second in a series conducted by the National Center for Environmental Assessment (NCEA) to further the development of a research strategy for completing comprehensive environmental assessments of nanomaterials.  The basis of the workshop was the report Nanomaterial Case Study:  Nanoscale Silver in Disinfectant Spray.  According to the summary report, the outcomes of this and future workshops in the series -- prioritized information gaps and risk tradeoffs -- will be used in developing and refining a long-term research strategy to assess potential human health and ecological risks of nanomaterials and to manage associated risks of specific nanomaterials.

The goal of this workshop was to prioritize responses to the question of what research or information is most needed to conduct a comprehensive environmental assessment of nanoscale silver used in disinfectant spray? The workshop used the nominal group technique (NGT) as the collective judgment tool to facilitate the discussion and prioritization of information needs among the group of diverse participants. The summary report lists prioritized research questions within the following research themes:

1.         Analytical Methods (120 points, 19 votes);

2.         Exposure and Susceptibility (120 points, 17 votes);

3.         Physical and Chemical Toxicity (115 points, 16 votes);

4.        Kinetics and Dissolution (98 points, 15 votes);

5.         Surface Characteristics (81 points, 14 votes);

6.         Sources and Release (76 points, 15 votes);

7.         Mechanisms of Nanoscale Silver Toxicity (72 points, 11 votes);

8.         Test Methods -- Mammals/Humans (67 points, 11 votes);

9.         Ecotoxicity Test Methods (59 points, 10 votes);

10.       Is New Nano Unique? (59 points, 10 votes);

11.       Biological Effects (56 points, 10 votes);

12.       Ecological Effects Required for Risk Assessment (43 points, 9 votes);

12.       Communication, Engagement, and Education (43 points, 9 votes);

14.       Fate and Transport of Nano-Ag (39 points, 12 votes);

14.       Adequacy of Current Data (39 points, 6 votes);

16.       Dissolution (36 points, 9 votes);

17.       Information from Manufacturers (35 points, 10 votes);

17.       Adaptive Tolerance/Resistance (35 points, 8 votes);

19.       Metrics (33 points, 7 votes);

20.       Kinetics II (22 points, 5 votes);

21.       Benefits (9 points, 5 votes);

22.       Incentivize Research for Comprehensive Environmental Assessment (CEA) (8 points, 1 vote); and

23.       CEA Framework (1 point, 1 vote).