EDTA disodium salt dihydrate

Tetrasodium EDTA is the salt resulting from the neutralization of ethylenediaminetetraacetic acid with four equivalents of sodium hydroxide (or an equivalent sodium base). It is a white solid that is highly soluble in water. Commercial samples are often hydrated, e.g. Na₄EDTA^.4H₂O. The properties of solutions produced from the anhydrous and hydrated forms are the same, provided they are at the same pH.

It is used as a source of the chelating agent EDTA^4-. A 1% aqueous solution has a pH of approximately 11.3. When dissolved in neutral water, it converts partially to H₂EDTA^2-. Ethylenediaminetetraacetic acid is produced commercially via the intermediacy of tetrasodium EDTA.