Atom economical and safe epoxidations of a variety of fatty acid methyl esters (FAMEs, including methyl oleate, methyl linolenate, methyl linoleate, and methyl soyate) under near-isothermal conditions are demonstrated using a tungsten-based Venturello catalyst and H2O2 as an oxidant under solvent-free conditions. By systematically optimizing the substrate/catalyst ratio, stirring rate, H2O2 addition rate, and external cooling rate, safe operation with minimal temperature rise was demonstrated in a semibatch reactor for each of the substrates with total selectivity toward the epoxides at complete conversion. In the case of methyl oleate epoxidation, which produces only one epoxide as product, intrinsic conversion/selectivity data obtained under near-isothermal (+/- 0.1 degrees C) conditions were regressed with suitable kinetic and reactor models to obtain an activation energy of 85 +/- 6.8 kJ/mol. These results provide valuable guidance for the rational design, scaleup, and safe operation of FAME epoxidation reactors.