Where Are We Heading in Nanotechnology Environmental Health and Safety and Materials Characterization?

E very chemist, material scientist, physicist, engineer, and commercial enterprise involved in the synthesis and/or production of engineered nanomaterials (ENM) or nanoenabled products aspires to develop safe materials. Nanotechnology environmental health and safety (nanoEHS) is a research discipline that involves the study of the possible adverse health and biological effects that nanomaterials may have on humans and environmental organisms and ecosystems. Recent nanoEHS research has provided a body of experimental evidence indicating the possibility of hazardous outcomes as a result of the interactions of unique ENM physicochemical properties with similar scale processes occurring at a wide range of nano/bio interfaces, including at the biomolecular, cellular, subcellular, organ, systemic, whole organism, or ecosystem levels. This projected hazard and risk potential warrants rigorous attention to safety assessment, safe use, safe implementation , benign design, regulatory oversight, governance, and public awareness to address the possibility and prevention of nanotoxicity, now and at any time in the future. 1 Thus, we must understand the properties of the ENMs that are responsible for the toxicological response, so that we can re-engineer their physicochemical characteristics for risk prevention and safer ENM design. 2 However, in spite of widespread use, no human toxicological disease or major environmental impact has been reported for ENMs. Thus, while " nanotoxicology " is a thriving subdiscipline of nanoEHS, the use of the " root " word toxicology may elicit a feeling that nanomaterials are inherently toxic despite the fact that toxicity has not thus far been established in real life. As a community, we may want to rename this subdiscipline as " nanosafety " since the objective is to use toxicology information to guide the design of safer nanomaterials for use in medicine, biology, electronics, lighting systems, and other areas. At ACS Nano, we publish articles and forward-looking Perspectives and reviews that determine and establish ENM physicochemical properties, structureÀactivity (SA) relationships , catalytic effects at the nano/bio interface, mechanistic injury responses, in vitro to in vivo prediction making, safer-by-design strategies, actionable screening and detection methods, hazard and risk ranking, fate and transport, ENM categorization, theory and modeling, societal implications, and regulatory/governance decisions. 3 Context is important in the immediate and long-range impact of this research, as we are interested in realistic nanoEHS exposure scenarios conducted with systematic variation of ENM physicochem-ical properties rather than investigations of a single or a limited number of materials in isolated in vitro studies that only …