The interface of science and law is a territory frequently occupied by policymakers. In facilitating this interface, epistemic communities have become significant influencers in policymaking, especially at the European Union (EU) level, as a result of its complex multilevel governance system. In this article we assess the quality and nature of interactions between epistemic communities and EU stakeholders on the Horizon-funded project ‘PrecisionTox’, by deploying the concept of epistemic communities developed by Haas, as well as the learning modes of epistemic communities as presented and adapted by Dunlop. The overarching goal of PrecisionTox is to advance the safety assessment of chemicals by establishing a new, cost-effective testing paradigm built from evolutionary theory, which entails reduction, replacement, and refinement of mammalian testing (the 3Rs). The study shows that EU-funded projects can provide an excellent platform for building epistemic communities and forging alliances with EU policymakers, especially when novel technologies may be unlocked and socialized. This study also explores the early interaction of policymakers with epistemic communities through different forms of learning to better understand the complexities surrounding these new technologies in order to set an agenda for policy interventions.