Sulfhydryl odors in organothiophosphate formulations are suppressed by treatment of the thiophosphate compound (e.g., bensulide) during preparation of the formulation with a selected emulsifier agent, ethoxylated tallow amine. The amine and any reacting products resulting from the treatment are retained in the final formulation. The amine will continue to react with the mercaptan and other sulfhydryl compounds formed by the continuing degradation of the thiophosphate compound, thereby providing further odor control.