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 Monoaromatics


1,2,4-Trichlorobenzene (1,2,4-TCB) is used primarily as an intermediate for the production of herbicides, pigments, and dyes (79%); as a process solvent (14%); and as a dye carrier (7%). It is also used as a process regulator (additive or lubricant) (OSPAR 2005).

EPA's Toxics Release Inventory reports that 26,340 pounds of 1,2,4-TCB were released or disposed of in 2007. As all facilities are not required to report, this is a minimum estimate. The releases generally were point source or fugitive emissions to the air (21,881 pounds) or deep well injections (3,700 pounds).

In a 1999-2002 U.S. Geological Survey nationwide assessment of water quality in public and private water wells, 1,2,4-TCB was not detected in domestic or public supply wells, nor was it found in aquifer samples (Zogorski et al. 2006).


1,2,4-Trichlorobenzene, CASRN: 120-82-1
PubChem, National Center for Biotechnology Information.

OSPAR Commission, ISBN: 1-904426-10-7, Publication 2005/170, 40 pp, 2005

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