[3] E number: E433 Brand names: Polysorbate 80 is used as an emulsifier in foods, though research suggests it may "profoundly impact intestinal microbiota in a manner that promotes gut inflammation and associated disease states.

[7] Adding polysorbate prevents milk proteins from completely coating the fat droplets.

Polysorbate 80 is also used as a surfactant in soaps and cosmetics (including eyedrops), or a solubilizer, such as in a mouthwash.

Polysorbate 80 is also an excipient that is used to stabilize aqueous formulations of medications for parenteral administration, and used as an emulsifier in the making of the antiarrhythmic amiodarone.

[14] Some mycobacteria contain a type of lipase (enzyme that breaks up lipid molecules); when these species are added to a mixture of polysorbate 80 and phenol red, they cause the solution to change color, so this is used as a test to identify the phenotype of a strain or isolate.