1. Emulsifier – Allows water and oils to remain mixed together to form an emulsion, such as in mayonnaise, ice cream, and homogenized milk
Polysorbate are often used as emulsifier in some pharmaceuticals and food preparation. They are also used in cosmetics to solubilize essential oils into water-based product and in medical products, such as cream treatments for acne, and topical treatments for mouth sores.
Polysorbates are oily liquids derived from PEG-ylated sorbitan (a derivative of sorbitol) esterified with fatty acids. The number 60 following polysorbate refers to the fatty acid chemically associated with the polyoxyethylene sorbitan component of the molecule, i.e. monostearate.
Polysorbate 60 is approved to use as a food additive with E number 435 in EU and generally recognized as safe food substance in US.
Scientific References :
1. PubChem: https://pubchem.ncbi.nlm.nih.gov/compound/22833389
Regulatory References :
1. EU Approved Food Additive 
2. US FDA Food Additives Status List 
3. US FDA Generally Recognized As Safe (GRAS) Food Substances