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, characterized in that the formulation satisfies 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 ration 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 excluded. The formulation may comprise a pesticide or herbicide. The action of the evaporation retardant is improved.

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.

Abstract: An electrically energized vaporizing unit for medications, room deodorizers, room scenting compounds, room insecticides, and the like, which is simple and inexpensive in its construction and which is compact in size. The vaporizing unit includes a housing having a central slot for holding a compressed paper fiber pad which is impregnated with the substance to be vaporized. The pad is heated by a pair of electrical heating elements which are located in the housing and positioned on opposite sides of the slot for maximum vaporizing efficiency of the pad. The housing may also contain paraffin wax. The melting point of the wax is selected to correspond to the vaporizing temperature of the particular substance in the pad. The vaporizing unit is provided with an electric plug which may be directly plugged into an electric receptacle to energize the PTC heating elements, and it does not require a switch or protective thermostat.