CAS number
- 67-66-3
Molecular formula
- CHCl3
Formula weight
- 119.4 g/mol
Family
- Chlorinated aliphatic hydrocarbons (CAH)
Compound properties list|
| Melting/boiling point | -137 °C / 12 °C | Liquid |
| Relative density | 1.48 g/cm3 | Sinks in water |
| Vapour pressure | 170 mm Hg | Very volatile |
| Vapour density | 4.1 | Denser than air |
| Solubility in water | 7,000 mg/L | Moderately soluble |
| Henry's law constant | 3 x 10-3 atm·m3/mol | Rapid volatilization when dissolved |
| log Koc (Depending on soil or sediment characteristics) | 1.5 - 2.0* | Moderate adsorption to organic matter |
At 20 0C, chloroform is a liquid denser than water and very volatile. Characterized by
moderate solubility, it will volatilize rapidly once dissolved and adsorbs moderately to organic
matter. During a spill, the majority of the compound evaporates but may also enter into the soil or
migrate into a waterway. Once it encounters water (surface or subsurface), the chloroform will
dissolve or sink until it reaches an impermeable surface. The liquid chloroform that accumulates in
a saturated zone will gradually dissolve before volatilization occurs. The adsorbed chloroform in
the vadose and saturated zones will rapidly disappear, liberating contamination in either the
gaseous or dissolved state. The resulting plumes (gaseous or dissolved) will be relatively large in
size.
Chloroform should be handled with care as it is toxic.
Chloroform is produced industrially by either the chlorination of methane or the
chlorination of chloromethane. Canada has not produced chloroform since 1976, but continues to
import chloroform. Nearly all the chloroform produced is used to make other chemicals, primarily
chlorodifluoromethane (HFC-22) (HFC-22) (hydrochlorofluorocarbon-22), which is used as a refrigerant, and
in the production of fluoropolymers. HCFC-22 is one of the few fluorocarbons not restricted by the
Montreal Protocol on ozone depleting chemicals. Other miscellaneous uses include aerosol propellant,
solvent and degreasing agent, spot remover in dry cleaning, solvent for the industrial,
pharmaceutical and analytical chemistry, heat transfer medium in fire extinguishers, and
intermediate in the preparation of dyes and pesticides.
Chloroform enters the environment from chemical companies and paper mills. It is also found in
wastewater from sewage treatment plants and drinking water to which chlorine has been added.
Chlorine is added to most drinking water and many wastewaters to destroy bacteria. Small amounts of
chloroform are formed as an unwanted product during water chlorination.
Agency for Toxic Substances and Disease Registry (ATSDR). 1997.
Toxicological Profile for Chloroform. U.S.
Department of Health and Human Services, Public Health Service, Georgia, USA. (Viewed March 2010)
Canadian Council of Ministers of the Environment, 1999. Canadian Water Quality
Guidelines for the Protection of Aquatic Life: Halogenated Methanes, Trichloromethane
(Chloroform). In: Canadian Environmental Quality Guidelines. Canadian Council of Ministers of
the Environment, Manitoba, Canada. (Viewed
March 2010)
Montgomery, John H. 2007. Groundwater Chemicals, Desk Reference, Fourth Edition, CRC Press,
Taylor and Francis Group, Florida, USA.
