There are many different types of emulsifiers. The main function of an emulsifier is to prevent oil and water ingredients from separating in an emulsion. There are 2 main types of emulsifiers namely oil-in-water and water-in-oil. Water-in-oil emulsifiers are mostly used in fatty formulations such as sunscreens and night creams whereas oil-in-water emulsifiers are rather used in moisturising formulations such as day creams, lotions and other moisturising creams. There are also special emulsifiers that can be used for sprays and mists and assist in stabilising the formulation. Some of these include polysorbate-20, polysorbate-80, PEG-40 and PEG-7.