Fenpropathrin is a pyrethroid insecticide. It is a slow activator of voltage-gated sodium channel 1.8 (Nav1.8). Fenpropathrin induces mortality in the two-spotted spider mite (T. urticae) with an LC50 value of 2.35 g AI/L in a slide-dip assay. It has been found in watershed sediment samples. Formulations containing fenpropathrin have been used as insecticides in agriculture.