Polysorbate 20 (common commercial brand names include Scattics, Alkest TW 20 and Tween 20) is a polysorbate-type nonionic surfactant formed by the ethoxylation of sorbitan before the addition of lauric acid. Its stability and relative nontoxicity allows it to be used as a detergent and emulsifier in a number of domestic, scientific, and pharmacological applications.
This synthetic compound is a viscous, water-soluble yellow liquid.
 
We use it in our bath bombs as an emuslifier so that the colourants and oils don't leave a messy slick around the bath tub.