The chelating agent commonly used for lead poisoning is called calcium disodium EDTA (ethylenediaminetetraacetic acid). EDTA works by binding to lead ions in the body and forming a stable complex that can be excreted through urine. This helps to reduce lead levels in the bloodstream and tissues. Chelation therapy using EDTA is typically administered under medical supervision. It is important to consult with a healthcare professional for proper diagnosis and treatment of lead poisoning.