Tetrachloroethylene is an industrial solvent and dry cleaning chemical. It enters water from industrial sites and dry cleaners, causing liver damage and increasing cancer risk.

Tetrachloroethylene, also known as perchloroethylene or "perc," is a volatile organic compound widely used in industry and dry cleaning. It can enter water supplies through spills or improper disposal at industrial sites and dry cleaners. The EPA regulates this clear, colorless liquid with a sweet odor in drinking water, measuring it in parts per billion. Its widespread use began in the mid-20th century, leading to environmental concerns and stricter regulations over time.