Laureth-7 as an Emulsifier contains molecules that have at least 2 distinct sides, (typically) one side that is compatible with water, and one side that is compatible with oils or waxy materials. They are added to cosmetic products to enable the mix of non-mixable liquids to make them compatible and stable over time.Laureth-7 as a Surfactant (Surface active) is an organic compound which helps to reduce surface tension of substances to be mixed or emulsified. An example in cosmetics is the skin or hair cleansing property: water can be mixed with oil, sebum and dirt so that they can be rinsed away.