| Chemical |
Chloroprene |
| CAS-number : |
126-99-8 |
| |
| Synonyms : |
| 1,3-Butadiene, 2-chloro- |
| 2-chloro-1,3-butadiene |
| beta-chloroprene. |
| kloropreeni |
| |
| Sumformula of the chemical : |
| C4H5Cl |
| EINECS-number : |
| 2048180 |
| |
| Uses : |
Manufacture of neoprene.
|
| |
| State and appearance : |
Colourless liquid.
|
| |
| Odor : |
characteristic slightly etheric, threshold odour concentration
recogn. 0.40 mg/m3 = 0.11 ppm, Leonardos et al. 1969
|
| |
| Molecular weight : |
88.5 |
| |
| Spesicif gravity (water=1) : |
| 0.958 |
at 20°C |
| |
| Vapor density (air=1) : |
| 3.06 |
|
| |
| Conversion factor, 1 ppm in air=_mg/m3 : |
| 3.68 |
|
| |
| Conversion factor, 1 mg/m3 in air=_ppm : |
| 0.27 |
|
| |
| Vapor pressure, mmHg : |
| 118 |
at 10°C |
| 200 |
at 20°C |
| 275 |
at 30°C |
| 174 |
at 20 °C, Boublik et al. 1984 |
| |
| Melting point, °C : |
| -130 |
|
| |
| Boiling point, °C : |
| 59.4 |
|
| |
| Flashing point, °C : |
| -20 |
|
| |
| Log octanol/water coefficient, log Pow : |
| 2.03 |
GEMS 1982 |
| |
| Henry's law constant, Pa x m3/mol : |
| 3242 |
est. by bond contribution method, Hine & Mookerjee 1975 |
| |
| Volatilization : |
Using the estimated value for the Henry's Law constant, the
volatilization half-life from a model river 1 m deep with a
current velocity of 1 m/sec and a wind speed of 3 m/sec is
estimated to be approx. 3 hours (Lyman et al. 1982).
The relatively high vapor pressure suggests that chloroprene
would volatilize rapidly from dry soil surfaces.
Chloroprene is
also expected to volatilize fairly rapidly from wet surfaces
since its Koc values are relatively low and its estimated value
for Henry's Law constant is relatively high (Howard 1989).
|
| |
| Adsorption/desorption : |
Based on a method of molecular topology and quantitative
structure-activity analysis, a soil adsorption coefficient of
50 (Koc) was estimated for chloroprene (Sabljic 1984).
Using a linear regression equation based on an estimated log
octanol/water partition coefficient, a Koc of 315 was
estimated (Lyman et al. 1982).
|
| |
| Mobility : |
The Koc values suggest that adsorption to suspended solids and
sediments in water would not be significant.
Chloroprene should
be moderately to highly mobile in soil (Swann et al. 1983).
|
| |
| Other physicochemical properties : |
Slightly soluble in water.
Flammable, dangerous fire risk, explosive limits in air 4.0 to
20%.
Toxic by ingestion, inhalation, and skin absorption.
|
| |
| Photochemical degradation in air : |
The half-life for the reaction of chloroprene vapor with
photochemically generated hydroxyl radicals in the atmosphere
has been estimated to be 1.8 hours (estimated reaction rate
constant 1.36x10-10 cm3/molecule-sec at 25 °C and an ambient
hydroxyl radical concentration 8.0x10+5molecules/cm3).
The half-life for the reaction of chloroprene vapor with ozone
has been estimated to be 12 hours (an estimated reaction
constant 2.6x10-17 cm3/molecules-sec and an ambient ozone
concentration 6x10+11 molecules/sec)Based on these data, the
overall reaction half-life of chloroprene vapor in the
atmosphere has been estimated to be 1.6 hours (GEMS 1986).
Anticipated reaction products include H2CO, H2C=CClCHO, OHCCHO,
ClCOCHO, H2CCHCClO, chlorohydroxy acids and aldehydes (Cupitt
1980).
Photooxidation half-life in air:
27.8hr - 2.9hr, based upon estimated rate constants for
reaction with hydroxyl radicals and ozone in air (Howard 1991).
|
| |
| Half-life in air, days : |
| 1.16 |
27.8hr - 2.9hr, |
| 0.12 |
scientific judgement based upon estimated rate constants for reaction with hydroxyl radicals and ozone in air, |
| |
Howard 1991 |
| |
| Half-life in soil, days : |
| 180 |
6mo - 4w, |
| 28 |
scientific judgement based upon estimated unacclimated aqueous aerobic biodegradation half-life, |
| |
Howard 1991 |
| |
| Half-life in water, days : |
| 180 |
6mo - 4w, |
| 28 |
in surface water: scientific judgement based upon estimated unacclimated aqueous aerobic biodegradation half-life. |
| 360 |
12mo - 8w, |
| 56 |
in ground water: scientific judgement based upon estimated unacclimated aqueous aerobic biodegradation half-life, |
| |
Howard 1991 |
| |
| Aerobic degradation in water : |
Aerobic half-life:
6mo - 4w, scientific judgement based upon aqueous aerobic
screening test data for vinyl chloride (Howard 1991).
|
| |
| Anaerobic degradation in water : |
Anaerobic half-life:
24mo - 16w, scientific judgement based upon estimated
unacclimated aqueous aerobic biodegradation half-life (Howard
1991).
|
| |
| Other information of bioaccumulation : |
The bioconcentration factor of chloroprene has been estimated
to be 22 based on an estimated log octanol/water partition
coefficient (Lyman et al. 1982).
|
| |
| LD50 values to mammals in oral exposure, mg/kg : |
| 670 |
LD100 orl-rat, Patty 1967 |
| |
| LC50 values to mammals in inhalation exposure, ppm : |
| 829 |
LD100 ihl-rat 1hr |
| 277 |
LD0 ihl-rat 1hr, Patty 1967 |
| |
| Health effects : |
Man: loss of hair
|
References |
| 2974 | Boublik, T.
K. et al. 1984.
The Vapor Pressures of Pure
Substances. vol 17 Amsterdam, Netherslands: Elsevier Sci Publ. |
| 1676 | Cupitt, L.T. 1980.
Fate of toxic and hazardous materials in the
air environment.
Research Triangle Park, North Carolina, US
Environmental Protection Agency, Environmental Sciences
Laboratory, Office of Research and Development (EPA No.
600/3-80-084, PB 80-221948. |
| 3034 | GEMS. 1987.
Graphical Exposure Modeling System.
CLOGP.
USEPA |
| 3133 | GEMS; 1986 -.
Graphical Exposure Modeling System.
FAP.
Fate of
Atmos Pollut.
|
| 3045 | Hine, J. & Mookerjee, P.
K. 1975.
J.
Org.
Chem. 40: 292 - 298.
|
| 3120 | Howard, P.H., Boethling, R.S., Jarvis, W.F., Meylan, W.M. &
Michalenko, E.M., Handbook of Environmental Degradation Rates,
1991.
Lewis Publicers, Inc., Chelsea, Michigan, U.S.A.,
pp. 725.
|
| 2960 | Lyman, W.
J. et al. 1982.
Handbook of Chemical Property
Estimation Methods.
Environmental behavior of organic
compounds.
McGraw-Hill New York. |
| 1644 | Patty, F.A. 1967.
Industrial hygiene and toxicology.
Vol 2.
Interscience Publishers. |
| 2999 | Sabljic, A. 1984.
J.
Agric.
Food Chem. 32: 243 - 246. |
| 1598 | Stern, A.C. 1968.
Air Pollution.
Vol. 3, Academic Press N.Y.,
London. 661 pp. |
| 2988 | Swann, R.
L. et al. 1984.
Res.
Rev. 85: 17 - 28.
|
| 1468 | Verschueren, K. 1983.
Handbook of environmental data of
organic chemicals.
Van Nostrand Reinhold Co.
Inc., New York.
1310 s. |
