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Vinyl chloride

DESIGNATIONS

CAS No.: 75-01-4
Registry name: Vinyl chloride
Chemical name: Chloroethene
Synonyms, Trade names: Monochloroethene, ethene monochloride, VC, VCM, Freon 1140
Chemical name (German): Vinylchlorid
Chemical name (French): Chlorure de vinyle
Appearance: colourless gas with slightly sweet odour; it is transported only in stabilised condition (using phenol and its derivatives) in pressurised cylinders.

BASIC CHEMICAL AND PHYSICAL DATA

Empirical formula: C2H3Cl
Rel. molecular mass: 62.50 g
Density: 0.9106 g/cm3 at 20C, 0.983 g/cm3 at -20C (liquid)
Relative gas density: 2.16
Boiling point: -13.4 to -14.0C
Melting point: -153.8 to -160.0C
Vapour pressure: 3,300 hPa at 20C; 4,500 hPa at 30C; 7,800 hPa at 50C
Flash point: -77 to -78C
Ignition temperature: 415C
Auto-ignition: 472C
Explosion limits: 3.8-31 vol%
Odour threshold: 4,000 ppm in air
Solvolysis/solubility: in water: 1.1 g/l at 25C;
soluble in oil, alcohol, chlorinated solvents and hydrocarbons;
enhanced by silver and copper salts due to complexing
Conversion factors: 1 ppm = 2.60 mg/m3
1 mg/m3 = 0.39 ppm

ORIGIN AND USE

Usage:
96-98% of vinyl chloride is used to make polyvinyl chloride (PVC) with the remaining 2-4% being utilised in the manufacture of specific chlorinated hydrocarbons such as 1,1,1-trichloroethane, 1,1,2-trichloroethane and vinylidene chloride. VC is used on a large scale to make polymers (ATRI, 1985). About 25% of the world's total chlorine production is required for the production of VC.

Origin/derivation:
Production is by way of the addition of hydrogen chloride to acetylene or by way of the decomposition of 1,2-dichloroethane with the formation of hydrogen chloride as a by-product. The polymer of vinyl chloride is polyvinyl chloride (PVC).

Production figures:

Worldwide 1985: 13,500,000 t (ULLMANN, 1986)
Worldwide: 10,000,000 t (RIPPEN, 1988)
EC 1977: 3,500,000 t (RIPPEN, 1988)
USA 1987: 3,800,000 t (RIPPEN, 1991)
Japan 1980: 1,656,000 t (ATRI, 1985)
Germany 1988: 1,459,000 t (RIPPEN, 1991)
France 1982: 1,150,000 t (ATRI, 1985)
Italy 1977: 750,000 t (RIPPEN, 1988)
Taiwan 1984: 492,000 t (RIPPEN, 1991)
Canada 1982: 408,000 t (ATRI, 1985)
Great Britain 1977: 405,000 t (RIPPEN, 1988)
Mexico 1984: 132,000 t (RIPPEN, 1991)

Toxicity

Mammals:
Mouse: TCLo 50 ppmv, 120 h intermitt. acc. RIPPEN, 1991
Rat: LD50 500 mg/kg, oral acc. RIPPEN, 1991
Rat: TCLo1) 6,000 ppm acc. RIPPEN, 1991
Rabbit: TCLo 500 ppm, inhalation (7 h/d during 6 months) acc. RIPPEN, 1991

Note:
1) Inhalation, 4h, 12th-18th day after conception

Characteristic effects:

Humans/mammals: This flammable, toxic and narcotic gas irritates the eyes, the skin and the respiratory tract. Repeated exposure damages the liver, kidneys and spleen; malignant tumours may occur. Toxic concentrations in air may occur without producing an alarming odour. VC is definitely carcinogenic and teratogenic (deformities and skeletal changes on inhalation) as revealed both by animal experiments and human exposure.

Thermal decomposition produces acidic gases which irritate the eyes, the nose and the throat.

ENVIRONMENTAL BEHAVIOUR

Water:
Vinyl chloride is persistent in water, if not evaporating. However, there are no known cases of damage to aquatic organisms (UBA, 1986). Accumulation in the aquatic food chain is unlikely (BUA, 1989).

Air:
On expansion, the pressurised gas forms cold mists which are denser than air. They evaporate easily and form toxic, explosive mixtures. Accumulation in the atmosphere is likely because of the physical and chemical properties of vinyl chloride.

Half-life:
Under normal environmental conditions, vinyl chloride is extremely persistent. Under anaerobic conditions its half-life in soil is more than 2 years. Aerobic degradation in sewage treatment plants and surface water in an isolated bacteria culture with 20-120 mg/l requires at least 5 weeks (UBA, 1986). OH radicals reduce the half-life to 66 h. The hydrolytic half-life is less than 10 years (calculated, 25C) (RIPPEN, 1991). The half-life in the troposphere is eleven weeks (abiotic degradation) (ATRI, 1985). An average half-life between 2.2 and 2.7 days is reported by the BUA (1989).

Degradation, decomposition products:
Photochemical oxidation results in the formation of HCl, CO and formyl chloride as well as formaldehyde. There is no photolysis of 10 mg/l in water at 300 nm over 90 hours. Biotic mineralisation is extremely slow.

Combination effects:
Vinyl chloride reacts with acetylene, chlorine, fluorine, oxidising agents and peroxides with considerable amounts of heat being generated. Polymers are formed. Light, heat and hydrogen sulphide act as polymerisation initiators.

ENVIRONMENTAL STANDARDS

Medium/
acceptor
Sector Country/organ. Status

Value

Cat. Remarks Source
Water: Drinkw EC

G

1 g/l

  1) acc. RIPPEN, 1991
Groundw NL

G

0.01 m g/l

  Reference acc. TERRA TECH, 6/94
Groundw NL

L

0.7 m g/l

  Intervention acc. TERRA TECH, 6/94
Waste water USA

G

50 g/l

  2) acc. RIPPEN, 1991
Air:   DDR

L

0.6 mg/m3

MIKK   acc. HORN, 1989
  DDR

L

0.2 mg/m3

MIKD   acc. HORN, 1989
Emiss. D

L

5 mg/m3

  mass flow > 25 g/h acc. TA Luft, 1986
Workp D

L

8 mg/m3

TRK 3) DFG, 1989
Workp D

L

5 mg/m3

TRK In other cases DFG, 1989
Workp DDR

L

30 mg/m3

  Long and short-time value acc. HORN, 1989
Workp SU

(L)

5 mg/m3

    acc. UBA, 1986
Workp USA

(L)

10 mg/m3

TWA 4) ACGIH, 1986
Workp USA

(L)

0.010 ppmv

TLV 5) acc. RIPPEN, 1989
Foodstuffs:   D

L

0.05 ppm

  Packaging acc. RIPPEN, 1989

Notes:

1) Sum of all chlorinated hydrocarbons except pesticides
2) 4 day average for special synthetics industry, direct introduction
3) Applies to existing installations
4) Clearly carcinogenic
5) Ambient air, California

Within the framework of the specifications governing the handling of carcinogens, there is a special regulation in Germany for vinyl chloride. Accordingly, the concentration in workplace air must not exceed 3 ppm, marking and mandatory investigation are regulated, personal protection equipment defined and cleaning measures described (VGB 113, 1982, Appendix, 1 vinyl chloride). Furthermore, the Appendix to the BAT list (DFG, 1989) describes the relationship between the substance concentration in workplace air and the substance/metabolite concentration in biological material (EKA values) for vinyl chloride as a carcinogenic substance. The following accordingly applies:

mg/m3 thiodiglycolic acid
2.6 1.8
5.2 2.4
10 4.5
21 8.2
42 10.6

Air vinyl chloride Sample: urine at end of shift/end of exposure

The Order Governing Vinyl Chloride Consumer Goods (1983) in Germany bans the marketing of articles with a monomeric vinyl-chloride content of > 1 mg/kg. No risk from foodstuffs is assumed as long as the detectable monomeric vinyl-chloride level does not exceed 0.01 mg/kg.

On the basis of the Order Banning PCB (superseded regulations enforced since 1978 in 1990) vinyl chloride cannot be used in the Federal Republic of Germany as a propellant for aerosols.

Vinyl chloride is a substance hazardous to water for which approval must be granted in line with 19a of the WHG if they are to be conveyed in pipelines.

Comparison/reference values

Medium/origin Country

Value

Source
Surface water:
New Jersey, 1977-79 USA

max. 570 g/l

acc. RIPPEN, 1991
Rhine, 1982 D

< 200 ng/l

acc. RIPPEN, 1991
Rhine tributaries D

<0.001-0.005 mg/l

acc. ATRI, 1985
Drinking water:
113 cities USA

0.05-0.18 g/l

acc. RIPPEN, 1991
100 cities, 1977 D

max. 1.7 g/l

acc. ATRI, 1985
Groundwater:
New Jersey, 1977-79 USA

max. 9.5 g/l

acc. RIPPEN, 1991
Nassau County USA

1.6-2.5 g/l

acc. RIPPEN, 1991
Sediment/soil:
Los Angeles Bay, 1980/81 USA

<0.5 g/kg

acc. RIPPEN, 1991
Sewage sludge USA

3-110 mg/kg

acc. RIPPEN, 1991
Air:
Clean-air zones D

6.6-24 g/m3

acc. ATRI, 1985
Taunus D

0.01 g/m3

acc. ATRI, 1985
Frankfurt a.M. D

21.8 g/m3

acc. ATRI, 1985
Industrial estate, Marl D

213 g/m3

acc. ATRI, 1985
Production facilities, 1980 NL

3-70 ppm

acc. RIPPEN, 1991
Dump gas, 1980-83 USA

max. 2,000 ppm

acc. RIPPEN, 1991
Animals:
Invertebrates, Los Angeles USA

<0.3 g/kg

acc. RIPPEN, 1991
Fish, liver USA

<0.3 g/kg

acc. RIPPEN, 1991
Foodstuffs:
Cooking oil in PVC packaging  

0.05-14.8 mg/kg

acc. ATRI, 1985
Butter/margarine in PVC packaging  

0.05 mg/kg

acc. ATRI, 1985
Alcoholic beverages  

0-2.1 mg/kg

acc. ATRI, 1985

Assessment/comments

The use of vinyl chloride must be avoided as far as possible because of its definite carcinogenic effect and its high persistence. Waste incineration is inadequate since incomplete combustion produces highly toxic pollutants (e.g. hydrochloric acid and TCDD). Special sources: ATRI (1985); DRAFT (1988). Polyvinyl chloride (PVC) should be substituted by other (non-chlorinated) materials wherever possible.


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