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)

Chemistry and Behavior

Halogenated Alkanes

Ethanes

1,2-Dichloroethane

1,2-Dichloroethane1,2-Dichloroethane (1,2-DCA, CAS# 107-06-2) has a vapor pressure of 70.1 mm Hg at 25oC (ATSDR 2001) and is a class IB flammable liquid (NIOSH 2005). ATSDR (2001) gives 1.48 for the log Kow of 1,2-DCA, a range of 1.28 to 1.62 for the log Koc, and 1.1 e-3 atm-m3/mole (20oC) for the Henry's constant. The solubility of the chemical is about 8,690 mg/L at 20oC, and its specific gravity is about 1.23 (ATSDR 2001). The ATSDR toxicological profile for 1,2-DCA contains a useful summary tableAdobe PDF Logo of the compound's physical properties.

The relatively low calculated Koc value for 1,2-DCA in soil indicates that 1,2-DCA is likely to move quickly through soil and sediment (ATSDR 2001).

Based on a Henry's law constant of 1.1x10-3 atm-m3/mol at 20oC, 1,2-DCA is expected to volatilize rapidly from water surfaces (ATSDR 2001). Modeling information for this chemical in the Hazardous Substances Data Bank (HSDB) suggests that the half life of 1,2-DCA is about four hours in a river one meter deep and about four days in a lake.

Because of its low Kow, bioaccumulation is not expected to occur to any significant extent. 1,2-DCA can be degraded by microbial action under aerobic and, to a more limited extent, anaerobic conditions (ATSDR 2001).

When released to the atmosphere, hydroxyl radicals are expected to degrade 1,2-DCA with a half life of about 73 days. The transformation products from the reaction of 1,2-DCA with hydroxyl radicals in the atmosphere include formyl chloride, chloroacetyl chloride, hydrogen chloride, and chloroethanol. Direct photolysis is not expected to occur (ATSDR 2001).

References

1,2-Dichloroethane
Hazardous Substances Data Bank (HSDB)
TOXNET, National Library of Medicine Web site.

Ethylene Dichloride
NIOSH Pocket Guide to Chemical Hazards
National Institute of Occupational Safety and Health, 2005

Toxicological Profile for 1,2-Dichloroethane
Agency for Toxic Substances and Disease Registry (ATSDR), 297 pp, 2001

For Further Information

DNAPL Site Evaluation Adobe PDF Logo
Cohen, R. and J. Mercer.
EPA 600-R-93-022, 369 pp, 1993

This document has a broad discussion of DNAPL site evaluation and contains a comprehensive table of physical properties of selected DNAPL chemicals, including 1,2-DCA, in its Appendix A.