Abstract: A formulation suitable for spraying or for dilution with water to form a sprayable preparation, the formulation comprising an active ingredient, optionally a carrier or solvent for the active ingredient, an emulsifier and an evaporation retardant where the formulation satisfies the following formula ##EQU1## where L is less than or equal to 15, A=700376, B=-1.51, C=0.8472, M.sub.oil is the weighted average relative molar mass of the oil phase M.sub.retardant is the weighted average relative molar mass of the retardant, and X=(M.sub.oil) 1.8/Y, where Y is the molar solubility ratio of the formulation, defined as the minimum number of moles of the oil phase which will dissolve the retardant, divided by the number of moles of retardant, provided that, in the formula above, any solvent which has no liquid phase at 27.degree. C. at atmospheric pressure is extruded. The formulation may include a pesticide or herbicide. The action of the evaporation retardant is improved.