Functions of Disodium EDTA in Cosmetic
Manufacturers frequently use this ingredient for a variety purposes. It primarily works as a preservative, chelator and stabilizer, but has also been shown to enhance the foaming and cleaning capabilities of a cosmetic solution. As a metal chelator, it counteracts the adverse effects of hard water by binding with heavy metal ions contained in tap water, which in turn prevents the metals from being deposited onto the skin, hair and scalp. This makes it a particularly useful ingredient for rinse-off products that inherently require water to come into contact with the skin. Essentially, this ingredient deactivates the metal ions through bonding with them, which inturn prevents cosmetic products from deteriorating, maintains its clarity and prevents it from smelling rancid. You can find this ingredient in virtually every personal care product including facial moisturizer/lotion, sunscreen, anti-aging treatment, cleanser, shampoo/conditioner, hair dye, body wash and eye cream.
The FDA permits this ingredient to be used as a food preservative, and the Cosmetic Ingredient Review (CIR) Expert Panel has assessed it as safe to use in OTC personal care products. Clinical tests have shown that standard concentrations of the ingredient do not irritate, sensitize or penetrate the skin. Though clinical data indicates that disodium EDTA is not well absorbed by the skin, it has been shown to enhance the dermal penetration of other ingredients contained in a product. Thus, cosmetic formulators must excersise caution when combining it with other ingredients potentially harmful if absorbed by the skin.
Furthermore, though research shows this ingredient to be generally non-carcinogenic and non-toxic, some studies suggest that disodium EDTA is weakly mutagenic (probably due to the fact that it binds with metals required for healthy cell division.) Similarily, large oral doses have lead to reproductive and developmental effects, once again, likely due to the fact that the ingredient binds with and deactivates metail ions that are required for normal reproduction and development.