EDTA, also known as ethylenediaminetetetraacetic acid, is an organic compound with the formula C10H16N2O8. This white, water-soluble solid is used to bind to iron (Fe2+/Fe3+) and calcium (Ca2+) ions to form soluble complexes in aqueous solutions. In this way, it dissolves Fe- and Ca-containing limes and renders the iron ions non-oxidizable. EDTA is available as several salts, notably disodium EDTA, sodium calcium edetate and tetrasodium EDTA, but they all function similarly.

The chemical and physical properties of EDTA are:

• Its molecular weight is 292.24 g/mol.
• Melting point is 240 °C.
• Its density is 0.86 g/cm3 (20 °C).
• pKa values are 2.0, 2.7, 6.16, 10.26.

The production method of EDTA is as follows:

• Mannich type reaction method: This is the most common production method of EDTA. EDTA is obtained by a Mannich-type reaction between ammonia, formaldehyde and phosphoric acid. This reaction is similar to the Kabachnik-Fields reaction.

Uses of EDTA include:

• Textiles and paper: In industry, EDTA is mostly used to bind metal ions in aqueous solution. In the textile industry, it prevents metal ion contaminants from discoloring dyed products. In the paper industry, EDTA prevents metal ions, especially Mn2+, from catalyzing the decomposition of hydrogen peroxide. Hydrogen peroxide is used in chlorine-free bleaching.
• Food additive: EDTA is also used as a food additive. EDTA is known by the code E385 and is used as a color preservative, antioxidant and stabilizer. It can be found in foods such as canned vegetables, fruit juice, mayonnaise, margarine, meat products.
• Cosmetics EDTA is also used in cosmetics. EDTA prevents the formation of limescale in products such as shampoo, soap, lotion, toothpaste and extends the shelf life of the product.
• Medicine: EDTA is also used in medicine. EDTA is used as an anticoagulant to prevent blood samples from clotting. It is also used to treat heavy metal poisoning.