Discloses an agrochemical formulation containing polyoxyethylene- polyoxypropylene sorbitan fatty acid monoester and an agrochemical active, wherein total sum of oxyalkylene units in sorbitan alkoxylate is from 5 to 38 and fatty acid is C5 to C29 fatty acid and the use of said compositions in the method of treating vegetation to control pest. Further disclosed are: polyoxyethylene-polyoxypropylene sorbitan monoesters, their concentrates and their use as agrochemical adjuvants.