Vinylchloride

75-01-4

Colourless gas or liquid

Ethereal odor. 
Sweet odor. 
Pleasant odor at high 
concentrations (HSDB 2001).

62.5

Based on Henry's Law constant, a half-life of 0.805 hr was
calculated for evaporation from a river 1 m deep with a current
of 3 m/sec and with a wind velocity of 3 m/sec (Lyman et al. 
1982).

Due to high Henry's Law constant and high vapor pressure,
volatilization from soil would be rapid; half-lives of 0.2 and
0.5 days were reported for volatilization from soil at 1 and
10 cm incorporation, respectively (Jury et al. 1984).

According to rough estmates, the half-lives for the evaporation
of vinyl chloride from wate bodies is given as follows:
Pond: t1/2 = 43.8 hr
Lake: t1/2 = 32.7 hr
River: t1/2 = 4.7 hr
(IUCLID 2001)

A Koc of 0.40 was reported in "standard soil" (Jury et al. 1984)

Based on the reported water solubility, a Koc of 56 was
estimated (Lyman et al. 1982).

Based on the reported and estimated Koc values, vinyl chloride
will be expected to be highly to very highly mobile in soil
(Swann et al. 1983).

Gas phase vinyl chloride is expected to degrade rapidly in air
by reaction with photochemically produced hydroxyl radicals
with an estimated half-life of 1.5 days (Perry et al. 1977).

Products of reaction in the atmosphere include
chloroacetaldehyde, HCl, chloroethylene epoxide, formaldehyde,
formyl chloride, formic acid and carbon monoxide
(Muller & Korte 1977).

In the presence of nitrogen oxides the reactivity of vinyl
chloride is higher with a half-life of 3 - 7 hours
(Howard 1989).

Photooxidation half-life in air:
9.7hr - 97hr,
based upon measured rate constant for reaction with hydroxyl
radicals in air (Howard 1991).

In water no photodegradation was observed in 90 hours; however,
degradation is rapid in the presence of sensitizers, such as
might be the case in humic waters, or free radicalsas might be
found in PVC manufacturing effluent streams (Callahan et 
al. 1979).

Photooxidation half-life in air 9.7hr - 97hr, based upon
measured rate constant for reaction with hydroxyl radicals
in air (Howard 1991).

Hydrolysis will not be a significant loss process (Mabey et al. 
1981)

Vinyl chloride was approx 50% (20%) and 100% (55%) degraded in 4
and 11 weeks, respectively, in the presence (absence) of sand by
methanogenic microorganisms under anaerobic conditions in
laboratory scale experiments (Brauch et al. 1987).

Aerobic half-life:
4w - 6mo, scientific judgement based upon aqueous screening
test data (Howard 1991).

Anaerobic half-life:
16w - 24mo, scientific judgement based upon estimated
unacclimated aqueous aerobic biodegradation half-life
(Howard 1991).

Vinyl chloride is readily metabolized by a soil Pseudomonas sp.
in resting cell suspensions. 
This process mechanism was
established to include a dehalogenation step that entails a
direct hydoxylation of the C-Cl pond producing acetaldehyde.

This product is further oxidized to hydrooxyacetic acid then to
carbon dioxide. 
The half-life for dechlorination, with cells
grown on 3-chloropropanol, was 1.3 hours at a cell dencity of
0.1 g/mL (HAZARDTEXT 2001).

Biodegradation:
type: aerobic
inoculum: activated sludge, adapted
concentration: 0.05 mg/l
degradation: 21.5 % after 5 day
(IUCLID 2000).

Biodegradation:
type: anaerobic
inoculum: groundwater bacteria
concentration: 400 µg/l realted to test substance
test condition: 20 °C, darkness
remark: half-life 4 - 10 weeks
(IUCLID 2000)

Tetrachloroehhylene (PCE) can be transformed by reductive 
dehalogenation to trichloroethylene (TCE), dichloroethylene, 
vinyl chloride (VC) under aerobic conditions. 
In addition 
14C-PCE was at least pertilly mineralized to CO2 (24 % in a 
continuous flow fixed-film methanogenic column with a liquid 
detention time of 4 days: uder different methanogenic 
conditions nearly quantitative conversion of PCE to VC was 
observed) (IUCLID 2000).

Based on the reported water solubility, a BCF of 7 was
estimated (Lyman et al. 1982).

Based on the estimated BCF, vinyl chloride will not be expected
to significantly bioconcentrate in aquatic organisms (Ly et al. 
1977).

Bioaccumulation was studied by application of 14C-labelled
vinyl chloride to algae (Chlorella fusca var. vacuolata), fish
(Leuciscus idus) and activated sludge from a municipal sewage
treatment plant. 
The following bioaccumulation factors (BFn)
were reported:
Activated sludge: BFn = 1,100 (n = 5 days)
Algae: BFn = 40 (n = 1 day)
Fish: BFn = <10 (n = 3 days)
(IUCLID 2000).