Dense nonaqueous phase liquids (dnapls)

Halogenated Alkanes

1,2-Dichloroethane

1,2-Dichloroethane (1,2-DCA) has been replaced as a solvent and degreaser by less toxic compounds. It once served as a solvent for processing pharmaceutical products; for fats, oils, waxes, gums, resins, and particularly for rubber; and in paint, varnish, and finish removers. It also was used as an insect fumigant for stored grains and in mushroom houses, a soil fumigant in peach and apple orchards, a cleaner for upholstery and carpets, a solvent in textile cleaning and metal degreasing, a lead scavenger in antiknock gasoline, a starting material for chlorinated solvents (e.g., vinylidene chloride), a dispersant for plastics and elastomers (e.g., synthetic rubber), an ore flotation compound, and an extractant in certain food processes. Therapeutically, 1,2-DCA was once used as a general anesthetic in place of chloroform, especially in ophthalmic surgery. It currently is used primarily to produce vinyl chloride (NTP 2005).

EPA's Toxics Release Inventory reflects both scaled-back use of 1,2-DCA and better industrial control. In 1988, on- or off-site disposal (primarily underground injection) and other releases (primarily to air) totaled 6,276,083 pounds of 1,2-DCA. By 2008, releases of the compound had dropped to 501,794 pounds. As some releases do not meet EPA's reporting requirements, this number must be considered a minimum estimate.

1,2-DCA has been detected in old releases from underground storage tanks (USTs) that contained leaded fuels. Approximately 135,000 UST releases were documented prior to 1979 (Johnson et al. 2000). 1,2-DCA was present in gasoline releases at sufficient concentrations to appear in groundwater at thousands of micrograms per liter, and field evidence indicates that the compound is mobile and persistent in groundwater (Falta 2004).

ATSDR (2007) reports detection of 1,2-DCA in at least 598 NPL sites. In 2005, EPA's Office of Underground Storage Tanks compiled a list of 80 projects treating 1,2-DCA at 70 Superfund sites (EPA 2006 Appendix B).

In a U.S. Geological Survey nationwide assessment of water quality in public and private wells, 1,2-DCA was detected in about 0.17 percent of samples, but none was above the federal MCL of 5 µg/L. Zogorski et al. (2006) recommended consideration of 1,2-DCA in a VOC trends monitoring program.

References

2007 CERCLA Priority List of Hazardous Substances That Will be the Subject of Toxicological Profiles and Support Document
Agency for Toxic Substances and Disease Registry (ATSDR), 44 pp + 11 appendices, 2007

Lead Scavengers Compendium: Overview of Properties, Occurrence, and Remedial Technologies
U.S. EPA, Office of Underground Storage Tanks, 2006

Ethylene dibromide (EDB) and ethylene dichloride (EDC; aka 1,2-dichloroethane or 1,2-DCA) are synthetic organic chemicals used in leaded gasoline as "lead scavengers" to prevent the buildup of lead deposits that foul internal combustion engines. This report addresses historical uses, physical and chemical properties and analytical methods, environmental transport and fate, toxicology, occurrence in drinking water, presence at LUST sites, and remediation and treatment technologies for EDB and EDC.

The Potential for Widespread Groundwater Contamination by the Gasoline Lead Scavengers Ethylene Dibromide and 1,2-Dichloroethane
Falta, R.
Proceedings of the Second International Symposium on Dynamics of Fluids in Fractured Rock, February 10-12, 2004.
Faybishenko, B. and P.A. Witherspoon, eds. Lawrence Berkeley National Laboratory, p 57-62, 2004

The Quality of Our Nation's Waters: Volatile Organic Compounds in the Nation's Ground Water and Drinking-Water Supply Wells
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

1,2-Dichloroethane (Ethylene Dichloride), CAS No. 107-06-2
Report on Carcinogens, Fourteenth Edition. U.S. Department of Health and Human Services, Public Health Service, National Toxicology Program (NTP), 2016

For Further Information

Reevaluation of VOC Contamination in Ground Water Prompted by Indoor Air Results
Palmer, J.L., D.S. Oliver, S.J. Steinmacher, B.L. Hall, and J.D. Case.
NGWA 2006: Petroleum Hydrocarbons and Organic Chemicals in Ground Water, Prevention, Assessment, and Remediation Conference, 6-7 November 2006
View abstract