This publication presents the data and findings of the risk assessment on N-phenyl-N-[1-(2-phenylethyl)piperidin-4-yl]oxolane-2-carboxamide (THF-F), carried out by the extended Scientific Committee of the EMCDDA on 7-8 November 2017. In March 2018, at its 61st regular session, the Commission on Narcotic Drugs (CND) decided to place tetrahydrofuranylfentanyl in Schedule I of the Single Convention on Narcotic Drugs of 1961 based on a recommendation by the World Health Organization. This recommendation was substantially supported by European data provided by the EMCDDA.