Dimercaprol (INN) or British anti-Lewisite (abbreviated BAL), is a compound developed by British biochemists at Oxford University during World War II. It was developed secretly as an antidote for Lewisite, the now-obsolete arsenic-based chemical warfare agent. Today, it is used medically in treatment of arsenic, mercury and lead, and other heavy metal poisoning.

See SN 2,3-dimercaptopropan-1-ol