U.S. EPA Contaminated Site Cleanup Information (CLU-IN)

U.S. Environmental Protection Agency
U.S. EPA Technology Innovation and Field Services Division

Dense Nonaqueous Phase Liquids (DNAPLs)

Environmental Occurrence

Halogenated Alkanes


1,1,1-Trichloroethane (1,1,1-TCA) was used as a solvent for adhesives (including food packaging adhesives) and in metal degreasing, pesticides, textile processing, aerosols, lubricants, cutting fluids and cutting oil formulations, drain cleaners, shoe polishes, spot cleaners, printing inks, and stain repellents. It was used in industry primarily for cold-cleaning, dip cleaning, bucket cleaning, and vapor degreasing operations of items such as precision instruments, molds, electrical equipment, motors, electronic components and instruments, missile hardware, paint masks, photographic film, printed circuit boards, generators, switchgears, semiconductors, high vacuum equipment, fabrics, and wigs. It also was used for on-site cleaning of printing presses, food packaging machinery, and molds and as a chemical intermediate in the production of hydrochlorofluorocarbons and vinyl chloride. It was used at one time as a food and grain fumigant (ATSDR 2006).

According to the 1990 amendments to the Clean Air Act and the Montreal Protocol, U.S. production of 1,1,1-TCA was to be reduced incrementally and phased out by January 2002; however, beginning January 1, 2002, and ending January 1, 2005, production of limited amounts of 1,1,1-TCA could be authorized by the Administrator for use in essential applications or for export to developing countries (ATSDR 2006).

EPA's Toxics Release Inventory reports that 418,658 pounds of 1,1,1-TCA were released or disposed of in 2008. As some releases do not fall under EPA's reporting requirements, this number must be considered a minimum estimate. Most of the releases were point source or fugitive emissions to the air.

1,1,1-TCA has been identified in at least 823 of 1,662 hazardous waste sites proposed for inclusion on the National Priorities List (ATSDR 2006).

In a nationwide U.S. Geological Survey assessment of water quality in public and private water wells, 1,1,1-TCA was detected in just over two percent of public supply wells, albeit at very low levels. The compound also was detected in about two percent of the samples taken from aquifers, which ranks it as the seventh most frequently found VOC in groundwater (Zogorski et al. 2006).


1,1,1-Trichloroethane, CASRN: 71-55-6
PubChem, National Center for Biotechnology Information.

The Quality of Our Nation's Waters: Volatile Organic Compounds in the Nation's Ground Water and Drinking-Water Supply WellsAdobe PDF Logo
Zogorski, John, Janet M. Carter, Tamara Ivahnenko, Wayne W. Lapham, Michael J. Moran, Barbara L. Rowe, Paul J. Squillace, and Patricia L. Toccalino
U.S. Geological Survey, USGS Circular 1292, 2006, 112 pp

Toxicological Profile for 1,1,1-Trichloroethane
Agency for Toxic Substances and Disease Registry (ATSDR), 2023