Nonionic surfactants carry no electrical charge and are available in a variety of chemical types. The main classes are alcohol ethoxylates, alcohol ethoxylates/propoxylates, ethylene oxide-propylene oxide copolymers, castor oil ethoxylates, amine ethoxylates, fatty acid esters and their ethoxylates. They are used in a wide range of applications where they provide useful characteristics including emulsification, solubilisation, wetting, dispersion, detergency, foaming and defoaming.