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


Production of trichlorofluoromethane (TCFM), also known as Freon-11, began in 1936. The compound was used primarily in coolants for air-conditioning and refrigeration; in blowing agents for foams, insulation, and packing materials; in propellants in aerosol cans; and as a solvent (Plummer and Busenberg 2000).

EPA considers TCFM a Class I ozone-depleting chemical and has banned all nonessential uses. The production phaseout of TCFM and other chlorofluorocarbons began in the 1990s. EPA's Toxics Release Inventory reports that 227,792 pounds of TCFM were released in 2008, mostly as direct or fugitive air emissions. This amount compares with the 10,216,568 pounds released by industry in 1991. These data do not account for any releases by non-manufacturing activities.

In a U.S. Geological Survey nationwide study of aquifers, TCFM was the tenth most common VOC found, with a presence in about one percent of the samples. TCFM also was found in about one percent of the public water supply wells sampled and in roughly two percent of domestic wells (Zogorski et al. 2006). An on-line search of EPA's CERCLIS database for trichlorofluoromethane returned 53 Superfund sites. For those sites where concentration data were given, most concentrations were very low, which compares well with the Zogorski et al. (2006) report, where TCFM found at very low levels in samples from groundwater and drinking water supply wells. A sampling of the data for the sites in CERCLIS indicates that TCFM often is a secondary contaminant that occurs with chlorinated ethenes and ethanes.


Chlorofluorocarbons Background
Plummer, L. and E. Busenberg
Excerpted from "Environmental Tracers in Subsurface Hydrology" (P. Cook and A. Herczeg eds.), Chapter 15: Chlorofluorocarbons, p 441-478, Kluwer Acadmic Press, 2000

The Quality of Our Nation's Waters: Volatile Organic Compounds in the Nation's Ground Water and Drinking-Water Supply WellsAdobe PDF Logo
Zogorski, J., J.M. Carter, T. Ivahnenko, W.W. Lapham, M.J. Moran, B.L. Rowe, P.J. Squillace, and P.L. Toccalino.
U.S. Geological Survey Circular 1292, 112 pp, 2006