摘要：This Article reviews regulatory attempts to define nanomaterials to date, including the European Commission’s definition. It then sets forth and explains why agencies should adopt what I am calling an information-forcing definition of nanomaterials. Nanomaterials implicate the same informational problem as many other substances or practices that are the subject of political and legal debate: that is, we (the public) know enough to know that there are some risks but not enough to specify and assess those risks. We know risks are posed by some kinds of small-scale materials in some contexts, but not enough is known to define the universe of which particular materials pose risk and which do not (or how much risk is posed by those materials that do pose risk). Regulators, therefore, do not know enough to specify the health and environmental risks from nanomaterials with any precision. Regulatory definitions are, therefore, needed that facilitate the production and sharing by industry of information about the small-scale materials they use, why they use them, and what behaviors those materials exhibit that may translate into human health and/or ecological risk. The regulatory definitions should be structured so as not only to force information from industry, but also to force, or at least encourage, agencies not to give in to powerful forces of bureaucratic inertia and stick with regulatory definitions even after emerging science and other public information suggest they are obsolete.
