1,1,1-Trichloroethane is an industrial solvent that can enter water from improper disposal. It was widely used as a degreaser but is now banned for most applications.

1,1,1-Trichloroethane, once a common industrial degreaser, entered water supplies primarily through improper disposal at manufacturing sites. Its use has been phased out due to environmental concerns. While banned for most applications since the 1990s, it may still be present in older contaminated sites. Water utilities typically detect it using gas chromatography. Although health effects from low-level exposure are not well-established, high concentrations may affect the nervous system.