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

Methanes

Table 1 presents common physical/chemical properties of the profiled halogenated methanes. All of these chemicals are expected to be highly mobile in the subsurface. With the exception of trichlorofluoromethane, which has a moderate potential for bioaccumulation, the bioaccumulation potential of all of the remaining chemicals is limited. All of the halogenated methanes are subject to anaerobic biodegradation, although biodegradation of carbon tetrachloride is slow. Methylene chloride and bromochloromethane are also biodegradable in an aerobic environment (Cohen and Mercer 1993).

Table 1.
Common Physical/Chemical Properties of Selected Halogenated Methanes
Chemical Specific Gravity (g/cc) Solubility (mg/L) Vapor Pressure (mmHg) Henry's Constant (atm-m3/mol) Log Koc Log Kow
Bromochloromethane 1.934 16,700 142 1.5 e-03 1.43 1.41
Bromodichloromethane 1.980 4,500 50 2.41 e-03 1.8 2.1
Bromoform 2.890 3,010 4 5.32 e-04 2.45 2.3
Carbon Tetrachloride 1.594 800 90 2.94 e-02 2.04 2.64
Chloroform 1.483 7,950 246 4.03 e-03 1.65-2.40 1.97
Dibromochloromethane 2.451 2,700 76 9.9 e-04 1.92 2.16
Methylene Chloride 1.327 20,000 349 2.03 e-03 1.4 1.3
Trichlorofluoromethane 1.487 1,100 802.8 9.7 e-02 2.2 2.53

For references and temperatures see individual chemical profiles

For Further Information

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