CAS number
- 75-35-4
Molecular formula
- C2H2Cl2
Formula weight
- 96.9 g/mol
Family
- Chlorinated aliphatic hydrocarbons (CAH)
Compound properties list|
| Melting/boiling point | -122 °C / 32 °C | Liquid |
| Relative density | 1.2 g/cm3 | Sinks in water |
| Vapour pressure | 550 mm Hg | Very volatile |
| Vapour density | 3.4 | Denser than air |
| Solubility in water | 1,500 mg/L | Moderately soluble |
| Henry's law constant | 2 x 10-2 atm·m3/mol | Rapid volatilization when dissolved |
| log Koc (Depending on soil or sediment characteristics) | 1.7 - 2.4* | Moderate adsorption to organic matter |
At 20 0C, 1,1-dichloroethene 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, this compound will primarily evaporate but may also enter into the soil or
migrate into a waterway. Once it encounters water (surface or subsurface), the 1,1-dichloroethene
will dissolve or sink until it reaches an impermeable surface. The liquid 1,1-dichloroethene that
accumulates in a saturated zone will gradually dissolve before volatilization occurs. The adsorbed
1,1-dichloroethene 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.
1,1-Dichloroethene should be handled with care as it is flammable, toxic and reactive.
1,1-Dichloroethene, also known as vinylidene chloride, is a man-made chemical produced
commercially by the dehydrochlorination of 1,1,2-trichloroethane with excess lime or caustic.
Although 1,1-dichloroethene is manufactured in large quantities, most of it is used as an
intermediate in organic chemical synthesis (vinylidene fluoride and 1,1,1-trichloroethane) and in
the production of polyvinylidene chloride copolymers. These polymers, which have been commercially
important since their introduction in the early 1940s, are used extensively in many types of
flexible packing materials, as flame retardant coatings for fiber and carpet backing, as well as in
piping, coating for steel pipes, and adhesive applications. The major application of polyvinylidene
chloride copolymers is the production of flexible films for food packaging.
Although 1,1-dichloroethene does not occur naturally, the breakdown of polyvinylidene chloride
products is also a source of 1,1-dichloroethene in the environment.
Agency for Toxic Substances and Disease Registry (ATSDR), 1994. Toxicological
Profile for 1,1-dichloroethene. U.S. Department of Health and Human Services, Public Health
Service, Georgia, USA. (Viewed March 2010).
Montgomery, John H. 2007. Groundwater Chemicals, Desk Reference, Fourth Edition, CRC
Press, Taylor and Francis Group, Florida, USA.
