Risks are high on the agenda in our society, to the extent that we might refer to the society as a risk society. Our society experiences emerging technologies, like nanotechnology. Different actors respond to this in a variety of ways. Among these are the consumers, an important, but neglected category of actors in this context. Arguably it is in our role as consumers we first encountered nanotechnology, in the form of nano-enabled products at the consumers market. What consumers think and do, reacting to the mixed messages about benefits and risks of nanotechnology, contributes to how the risk society (with regard to nanotechnology) is developed, and in that sense becomes operationalized. The theme of this thesis, is not just the responses of consumers (and how others perceive these) to the introduction of nanotechnology, but also a case study of how the risk society can be operationalized. One important mode of operationalization is articulations. An important contribution of this dissertation is the emphasis on the ‘work of definition’ that has to be conducted by consumers when being confronted with newly emerging (nano) risks. The commitments of consumers with nanotechnology are analysed and theoretically elaborated with the help of the theory of the Risk Society by Ulrich Beck. In the thesis, focus group studies are one situation where ‘work of definition’ can be observed and evolving outcomes can be traced. Further, the empirical data include stakeholder interviews, as well as content analysis of international advertisements for nano-enabled consumer products. A general finding is that consumers, in focus group interactions , do not limit themselves to risk, but more often discuss responsibilities. A recurrent storyline in the discussions of the focus groups is: “New is worrisome”; “But old is worrisome too” and finally “Yes, new is like old – but with possible added benefits”. Stakeholder interviews show optimism to nanotechnology and technology in general. Enactors experiment with marketing of nano-enabled products. A challenge for civil society organisations is to adopt knowledge-based policies and decision-making on the complex and dynamic developments of nanotechnology. The findings and analysis have relevance even for other emerging technologies.