Chelating agents 

Chelating agents are chemical compounds that react with metal ions to form a stable, water-soluble complex. They are also known as chelants, chelators, or sequestering agents.

Chelating agents have a ring-like center which forms at least two bonds with the metal ion allowing it to be excreted. Chelating agents are usually organic compounds (a compound that contains carbon).

Specific chelating agents bind iron, lead, or copper in the blood and can be used to treat excessively high levels of these metals. Chelating agents may also be used in the treatment of heavy metal poisoning.

(KEE-lay-ting AY-jent) A chemical compound that binds tightly to metal ions. In medicine, chelating agents are used to remove toxic metals from the body. They are also being studied in the treatment of cancer.

Ethylenediaminetetraacetic acid (EDTA) is a chelating agent can bind to metals via four carboxylate and two amine groups. It is a polyamino carboxylic acid and a colorless, water-soluble solid, which is widely used to dissolve lime scale. It is produced as several salts, notably disodium EDTA and calcium disodium EDTA.