Abstract In this article, we provide an in-depth analysis of the Regulation concerning the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH). Measured by the economic importance of the European chemicals industry and the environmental and health risks associated with it, the Regulation probably represents the most important piece of EU environmental regulation to date. We argue that the precautionary approach embodied in REACH has triggered a radical departure from past regulatory efforts that failed effectively to engage with contemporary regulatory challenges of scale, uncertainty, complexity and innovation. In effect, REACH is shaping a promising EU regime of responsive co-regulation that is without precedent in the forty-year history of EU environmental law. We believe that the success of this regime will not only determine the effectiveness of EU chemicals regulation, but more generally will come to determine the way in which EU regulation is likely to respond to a host of new technologies that shape our technological modernity.