Many active agents, such as insecticides, herbicides and fungicides are relatively insoluble in aqueous media. In order to apply them efficiently to crops it is thus necessary to formulate them in a manner that facilitates their dilution in the water based spray media used in practice, by the farmer or contract spray operator. The present invention relates to aqueous dispersions comprising a surface active agent and active agents such as insecticides, herbicides and fungicides, in particular such dispersions in which the particles are of sub-micron diameter, e.g. less than 500 nm. Preferably the particles have a zero charge and the active agent dispersed therein has an aqueous solubility of less than 100 ppm. The active agent(s) may comprise at least 25 wt%. Furthermore, there may be more than one active agent and the particle may also comprise an antifoam agent such as a polyetheralkanolamine comb polymer surfactant. A preferred composition comprises 23.0 % 3-(4-isopropylphenyl)-1,1-dimethylurea (Isoproturon), 9.2 % N-(2,4-difluorophenyl)-2-[3-(trifluoromethyl)[henoxy]-3-pyridinecarboxyamide (Diflufenican), 18.1 % Polyetheralkanolamine comb polymer (Jeffsperse (RTM) X3204) and 0.9 % Dimethylpolysiloxane fluid emulsion.
