A reversible composition consisting of a solid matrix wherein a pesticide is uniformly dis­persed or distributed within a solidifying agent. This composition comprises (i.) a liquid pesticide, solid pesticide or solution or dispersion thereof and (ii.) a solid surfactant or a surfactant capable of solidifying at room temperature selected from the group consisting of polyoxyalkylated alkyl phenols, polyaryl phenol ethoxylates, sorbitan fatty acids and polyoxyalkylated derivatives thereof, polyoxyalkylated branched or linear mono alcohols, diols or polyols, polyoxyalkylated esters, polyoxyalkylated fatty amines and ethylene oxide propylene oxide block copolymers. This solid matrix can be shipped without presenting substantial danger to either the environ­ment or animal life. The solid matrix may be trans­formed into a liquid state by heat and/or agitation.