The European Chemicals Agency (ECHA) announced on March 23, 2016, a new publication co-authored with the Dutch National Institute for Public Health and the Environment (RIVM) and Joint Research Center (JRC) that illustrates how to use data for different nanoforms within the same substance registration. According to ECHA, this approach “will form a cornerstone in the future guidance development on hazard assessment for nanoforms” at the European Union (EU) and Organization for Economic Cooperation and Development (OECD) level. ECHA describes the paper, “Usage of (eco)toxicological data for bridging data gaps between and grouping of nanoforms of the same substance: Elements to consider,” as a scientific reference paper. ECHA states that at the EU level, it offers regulators, researchers, industry, and non-governmental organizations (NGO) an approach of how to justify scientifically that studies on one nanoform of a substance can be used to predict the hazard properties of other forms of the same substance. The paper outlines a stepwise approach to identify opportunities for using data between nanoforms within the same substance registration. The identification is based on grouping through an assessment of physicochemical properties and in vitro screening methods. According to ECHA, this may allow for a hazard assessment of several nanoforms of the same substance, minimizing the testing needed, including testing on animals, and therefore also minimizing costs.