Tetrasodium edetate is a water-soluble ingredient used as a “chelator,” which means it binds to certain mineral ions to inactivate them. Through this action, it can prevent the deterioration of cosmetic and personal care products, as it stops the growth of mold and other microorganisms. It also helps maintain clarity, protect fragrance compounds, and prevent rancidity. One of its main uses it to help personal care products work better in hard water.
Int J Cosmet Sci. 2008 Aug;30(4):285-95. doi: 10.1111/j.1468-2494.2008.00447.x.
Journal of the German Society of Dermatology, July 2012, issue 7, pages 488-491
Clinical, Cosmetic and Investigative Dermatology, November 2010, issue 3, pages 135-142