Decades of research on environmental, health and safety impacts of nanomaterials have generated large amounts of nanosafety data, but not all data are available online following the Findable, Accessible, Interoperable, and Reusable (FAIR) principles. This lack of FAIR data delays progress in regulatory research, needed by regulators to develop evidence-based policies. In this context, researchers collaborating in the EU NanoSafety Cluster ( www.nanosafetycluster.eu) engaged in a discussion on the ethical impacts related to (not) sharing nanosafety data. Screening the potential ethical impacts suggested that openly sharing nanosafety data relevant to risk governance of nanomaterials could give rise to ethical issues related to health and to liberties, and that these data might be misused. On the other hand, not openly sharing such nanosafety data could raise issues related to health, equity, common good, environment, and sustainability. A small-scale Ethical Impact Assessment (EIA) was performed between June 2022 and April 2024 to identify and evaluate more specific ethical issues and to propose recommendations for remediating ethical concerns. Preliminary results were presented in scientific conferences (one poster and three oral presentations), while the comments of the participants were incorporated in the final version of the presented paper. The EIA identified ethical issues and value conflicts related to the following sectors: intellectual property, social justice, public health, dual use, environmental ethics and animal ethics. Some recommendations for remediation are the competence of research organisations. Other recommendations call for societal dialogue and engagement. Yet other recommendations call for political action.