Nanomaterials may call for a reconsideration of the present Japanese chemical regulatory system

The nanoscience world has gained the attention of science and technology and is expected to enable the increased understanding and regulation of material science. Although it is not clear what influence nanotechnology development will have on human society, it is necessary to address concerns for both users of the technology and citizens about its influence on the environment and health. Research on the implication of this technology on both health and the environment began with research and development activities of various nanotechnologies in the US and EU, including discussions of proper regulations. The Japanese system of chemical risk control for human health and environment protection, including the Industrial Occupational Safety and Health Law and the Chemical Substances Control Law, may not have sufficient flexibility for new substances, such as nanomaterials, derived from this emerging technology. We have paid little attention to either size-dependent risk or surface treatment/function of chemical substances. As for the certain range of material sizes, one needs to confirm whether such a definition is meaningful from the viewpoint of risk evaluation and control of chemical materials. One must conduct the risk evaluation of each nanomaterial in accordance with the process of existing chemical risk evaluation systems. The assessment of the risk of such nanomaterials will suggest a reconsideration of the existing systems.