by John C. Monica, Jr. and Carlean Ponder, guest contributors to Small Times
September 18, 2007 — The United States Environmental Protection Agency (EPA) held a public meeting on September 6 and 7, 2007 to discuss nanoscale material characterization issues accompanying the implementation of its proposed Nanoscale Materials Stewardship Program (NMSP) under the Toxic Substances Control Act. The meeting had 100 registered participants divided among government, academic, industry, trade association, environmental consulting, legal, and nongovernmental organizations.
EPA began considering the possibility of a voluntary stewardship program for nanoscale materials in 2005, and subsequently invited the public and stakeholders to participate in the development process beginning in October 2006. EPA published a NMSP concept paper in July 2007 after much scientific and public input. Following up on its July concept paper, EPA convened this public meeting in order to “help clarify which data and elements should be included in the NMSP.”
The expert advisory panel fielding questions at the meeting included two representatives from industry, four from government, and five from academia. The panel was given a set of 21 technical questions prior to the meeting to frame the issues most important to EPA. Many on the advisory panel provided written answers before the meeting and were given a chance to expand upon those answers at the meeting. The general public was also invited to ask questions, however, the meeting did not draw a lot of comments or questions from the public.
Primary areas of inquiry involved the (i) characteristics currently used or that should be used to characterize nanoscale materials for environmental, health, and safety purposes; (ii) rationale for selecting these specific characteristics; and (iii) identification of the issues regarding the use of these characteristics in the NMSP.
Several panel members advanced the notion that any characterization of nanoscale materials is premature at this point because of the evolving state of science in the field. Some contended EPA does not have enough information about the actual structure of nanoscale materials, both chemical and physical, to assign classifications that will be meaningful in the mid-to-long term.
One industry representative went so far as to advocate the abandonment by EPA of any plans to characterize nanoscale materials for NMSP purposes. He was concerned that any classification may ultimately lead to labeling all nanoscale materials “hazardous,” which the current scientific evidence does not support. EPA responded that material characterization of some sort is a necessary part of NMSP, without which the proposed program is unworkable.
The effect of material impurities on nanoscale material characterization was another major issue addressed at the meeting. The panelists and one public commentator were concerned that impurities in the materials could change material properties and even toxicity levels. This uncertainty might make consistent characterization difficult. One speaker noted an increasing recognition that toxicological endpoints observed for nanoscale materials may be particularly sensitive to morphology, surface effects, and contamination. The need to develop methods to obtain purer forms of the materials was also recognized along these same lines.
EPA also asked the panelists to comment on the current status of voluntary standardization efforts. Some panelists believed the U.S. is lagging behind its international counterparts in terms of developing voluntary nanotechnology standards. However, others noted the U.S. in participating in the International Organization for Standardization’s worldwide nanotechnology standardization efforts through the American National Standards Institute’s technical advisory committee 229 in order to “assist the efficient and effective development of world and local markets for nanotechnology products.” One panelist suggested labeling and isolating nanoscale materials that are truly different from micro materials will play an important role in the standardization process. Another recommended having a “combination” category for materials that do not fit neatly into any single category. Most agreed that it will be extremely difficult to write characterization standards that will apply to all nanoscale materials across the board.
Finally, beyond the many concerns they voiced, most panelists agreed that few, if any, nanoscale materials are fully understood at this point, and that while researchers and manufacturers are working on systems that will help with this analysis, these methods are still developing and will need to be evaluated for many years to come.
John C. Monica, Jr. and Carlean Ponder are attorneys with Porter Wright Morris & Arthur LLP.