This article on nanomaterial safety, the first in a two-part series, offers a primer on what risk managers need to know when considering measures to protect workers, as well as practical guidance on actions to improve safety in various work environments. The authors – scientists and attorneys – note that consideration of such issues now could pay substantial dividends later in terms of protection against liability. Because the regulatory process takes time, say the authors, “stakeholders may want to consider whether responsible stewardship requires filling the regulatory vacuum with voluntary best practices aimed at promoting workplace health and safety.” The second part of the series will focus on the adequacy of warnings in connection with nanomaterial products, and how manufacturers should craft a proper warning.